VETERINARY  STUDIES 


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THE  MACMILLAN  COMPANY 

NEW  YORK   •    BOSTON   •     CHICAGO   •    DALLAS 
ATLANTA   ■    SAN   FRANCISCO 

MACMILLAN  &   CO.,  Limited 

LONDON    •     BOMBAY    ■    CALCUTTA 
MELBOURNE 

THE  MACMILLAN  CO.  OF  CANADA,  Ltd. 

TORONTO 


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VETERINARY  STUDIES 


FOR 


AGRICULTURAL  STUDENTS 


BY 

M.  H.  REYNOLDS,  B.S.,  D.Y.M,  M.D. 

PROFESSOR    OP    VETERINARY    MEDICINE,    UNIVERSITY    OF    MINNE- 
SOTA;  MEMBER  INTERNATIONAL  COMMISSION  ON  CONTROL 
OF   BOVINE   TUBERCULOSIS;    MEMBER   AMERICAN 
VETERINARY    MEDICAL    ASSOCIATION 


EIGHTH  EDITION 


THE  MACMILLAN  COMPANY 
1922 

All  Rights  Reserved 


%',  ;  Jr'  ;  ^^'f  'r,.'  '*  I  ^/'^  /'paiNTJSD  IN   THE  UNITED   STATES   OF  AMERICA 


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Copyright,  1910,  and  1922, 
By  the  MACMILLAN  COMPANY, 


Set  up  and  electrotyped.      Published   December,   1910.     Reprinted  August,    1911. 
Eighth  edition. — Set  up  and  electrotyped.    Published  November,  1922. 

kviAlM  LIBRAKY. AGRICULTURE  DEKV 


PREFACE  TO  EIGHTH  EDITION 

I  WISH  to  thank  my  many  fellow  teachers  who  have  shown 
appreciation  by  continuing  to  use  this  textbook  in  spite  of  inac- 
curacies and  evident  need  of  revision.  I  wish  to  emphasize  again 
the  fact  that  Veterinary  Studies  is  intended  to  some  extent  as  a 
teacher's  outline.  Each  teacher  must  add  material  as  he  may 
think  wise,  or  leave  out  entire  subjects  according-  to  local  needs. 
I  find  that  very  many  pupils  taking  veterinary  class  work  in  ag- 
ricultural schools  need  review  work  on  physiology.  The  necessity 
for  a  practical  working  knowledge  of  physiology  is  evident. 
Some  knowledge  of  anatomy  is  plainly  necessary  in  order  that 
disease  processes  may  be  located,  and  that  students  may  under- 
stand animal  conformation.  Some  elementary  pathology  is 
absolutely  necessary  in  order  that  pupils  may  have  some  under- 
standing of  what  disease  processes  really  are. 

Causes  and  prevention  of  diseases  should  be  considered  as  of 
paramount  importance,  and  only  carefully  selected  diseases 
should  be  presented.  These  should  be  diseases  which  are  uniform 
in  symptoms  and  history  and  therefore  easily  recognized,  and  of 
such  diseases,  those  that  are  rather  easily  and  simply  treated  or 
are  preventable. 

There  may  be  perhaps  exception  to  this,  in  case  of  stock 
owners  who  do  not  have  access  to  trained  veterinarians.  In 
such  case  it  is  a  matter  of  plain  common  sense  that  they  must 
do  the  best  they  can  for  themselves. 

However,  we  veterinary  teachers  of  agi-icultural  students 
should  have  constantly  in  mind  the  fact  that  we  are  educating 
expert  stockmen — not  poorly  trained  quack  veterinarians.  The 
student  who  has  had  a  proper  course  should  better  appreciate 
the  competent  veterinarian  and  call  him  more  promptly  and 
intelligently. 

Appreciation  is  due  JP.  f^  A  1Iewitt,"Tr£  the  College  of  Agri- 
culture, University  of  ATiiiuoula,  for' >e^ wing  and  criticizing 
the  lectures  on  anatomy  and  phvsiologv. 

4083S2 

^^     *^  M.  II.  REYNOLDS. 

University  of  Minnesota, 
September,    1922. 


PKEFACE  TO  FIRST  EDITION 

During  ten  years'  experience  in  teaching  veterinary  subjects 
to  agricultural  students,  certain  difficulties  have  l)cen  constantly 
encountered.  Others  doing  this  work  have  probably  had  similar 
experience.  There  has  been  the  difficulty  of  imperfect  training, 
or  entire  lack  of  previous  training,  in  physiology  and  other  sub- 
jects which  medical  men  recognize  as  fundamental.  There  is 
always  present  the  difficulty  of  presenting  a  technical  subject 
in  untechnical  language ;  difficulty  in  securing  satisfactory  illus- 
trations; and  difficulty  in  giving  the  kind  and  character  of 
veterinary  work  which  is  generally  demanded  and  conceded  as 
necessary,  without  giving  our  students  a  sort  of  training  which 
will  turn  some  of  them  into  unqualified  practitioners.  There 
has  been  serious  difficulty  in  covering,  without  a  textbook,  a  sat- 
isfactory amount  of  ground.  Many  students  do  not  take  notes 
well. 

During  this  time  I  have  been  more  and  more  impi-essed  with 
the  belief  that  a  textbook,  wisely  illustrated  and  carefully  edited 
for  its  legitimate  use,  would  enable  me  to  cover  very  much  more 
ground  within  the  available  time. 

The  style  of  editing  that  has  been  adopted  was  selected  with 
a  view  to  presenting  the  subject  matter  to  students  in  a  con- 
spicuous and  easily  grasped  way.  This  must  be  our  excuse  and 
answer  to  criticism  which  the  expert  printer  may  legitimately 
make. 

This  work  has  been  written  more  particularly  as  a  text  for 
veterinary  classes  in  agricultural  schools  and  colleges;  but  it  is 
hoped  that  it  may  prove  helpful  also  to  stockmen  who  are  not 
able  to  attend  our  agricultural  colleges,  but  who  care  to  know 
more  of  the  animal  machines  with  which  they  are  working.  I 
take  this  occasion  to  deprecate  the  blind  dosing  of  stock  to  which 
farmers  and  stockmen  are  very  much  inclined.  The  student 
should  realize  the  impossibility  of  writing  a  prcscrii)tion  that  will 

vii 


viii  PREFACE  TO  FIRST  EDITION 

fit  all  cases  of  a  certain  disease,  and  he  will  hesitate  to  risk  the 
use  of  medicines  of  which  he  knows  very  little  in  diseases  of 
which  he  knows  less. 

Lecture  notes  which  have  been  collected  during  a  period  of  ten 
years  have  formed  the  basis  for  this  w^ork,  and  I  am  now  unable, 
in  many  cases,  to  give  credit  to  authorities  that  have  been  con- 
sulted, where  credit  is  fairly  due. 

Illustrations  have  not  been  used  in  any  case  merely  as  pic- 
tures. Every  one  is  intended  to  illustrate  something  and  make 
that  illustration  as  impressive  as  possible. 

Suggestions  to  the  teacher.  It  is  not  intended  that  this  text- 
book should  entirely  supplant  lecture  work.  On  the  contrary, 
nearly  every  lesson  may  be  supplemented  to  advantage  and  so 
give  opportunity  for  originality  and  the  greatest  effectiveness. 
It  will  be  readily  understood  that  certain  subjects  are  of  great 
importance  in  some  states,  and  unimportant  in  others.  Each 
teacher  should  add  what  he  thinks  best  for  his  grade  of  pupils 
and  his  local  needs. 

"When  time  permits  much  time  can  be  profitably  spent  on 
more  extended  anatomy  work,  especially  for  students  who  wish 
advanced  live  stock  work.  It  can  be  readily  illustrated  and 
easily  impressed :  for  instance,  that  smooth  or  rough  hips  de- 
pend upon  a  fraction  of  an  inch,  more  or  less,  on  the  external 
angle  of  the  ilium ;  and  that  high  or  low"  withers,  in  the  main, 
depend  upon  variations  in  the  length  of  the  superior  spinous 
processes  of  the  dorsal  vertebrae ;  and  that  conformation  depends 
upon  the  bony  skeleton  and  muscular  developments. 

IVIuch  time  with  considerable  actual  practice  should  be  given 
to  the  study  of  unsoundness ;  to  common  forms  of  lameness,  and 
the  types  of  conformation  which  tend  toward  these  unfortunate 
conditions.  Common  irregularities  of  the  teeth  are  easily  illus- 
trated in  classroom.  These  are  given  as  suggestions  and  to  im- 
press the  fact  that  this  text  is  not  expected  to  cover  the  entire 
field  of  veterinary  teaching  for  all  agricultural  colleges. 

I  respectfully  suggest  that  teachers  should  insist  upon  study 
of  illustrations.  In  my  own  class  work  I  find  the  constant  diffi- 
culty that  students  glance  at  the  illustrations  carelessly  and 
hurriedly,  and  thus  fail  to  get  the  benefit  which  they  might 
easily  have.    Students  may  be  selected  at  random  and  asked  to 


PREFACE  TO  FIRST  EDITION  ix 

draw  upon  the  board,  from  memory,  illustrations  from  the  les- 
son for  that  day.  After  a  few  practice  lessons  of  this  kind, 
students  easily  learn  how  to  study  textbook  illustrations. 

M.  H.  REYNOLDS. 
University  of  Minnesota, 
October,  1903. 


CONTENTS 


ANATOMY 

LECTURE  PAGE 

I.  ANATOMY 

Bones. — Kinds,  peculiarities,  development,  structure  and 
composition. 

Head. — Face,  cranial,  and  hyoid  bones;  dentition  of 
horses,  table;  dentition  of  cattle,  table;  estimating 
age  by  teeth;   original  application,  common  disorders         1 

II.  OSTEOLOGY 

Spinal  column. — General  characteristics  of  vertebrae. 
Cervical,  dorsal,  lumbar,  sacral,  and  coccygeal  ver- 
tebrae. 

Sternum.  Eibs.  Practical  application,  common  dis- 
orders         7 

III.  FRONT  LIMB 

Shoulder,  arm,  forearm,  and  foot — bones  of,  common 
disorders 10 

IV.  POSTERIOR  LIMB 

Pelvis,  thigh,  leg,  and  foot — bones  of,  practical  applica- 
tion,  disorders 14 

V.  FOOT 

Bones,  horny  hoof,  matrix,  plantar  cushion,  back  ten- 
dons, good  foot  described,  practical  application,  dis- 
orders of  the  foot 19 

VI.  ARTICULATIONS   (JOINTS) 

General  groups,  examples;   varieties  of  freely  movable, 

immovable,  slightly  movable. 
Structures   at  joints;    articulations   described,  practical 

application,  disorders 24 

VII.  MUSCULAR  SYSTEM 

Peculiar  property  of  muscle,  kinds,  classification,  parts, 
microscopic  structure,  source  of  heat  and  power, 
practical  application,  disorders 29 


^ii  CONTENTS 


LECTURE 


PAGE 


VIII.  NERVOUS  SYSTEM 

General  function,  nerve  centers. 

Cerebrospinal    system. — Brain,     cranial    nerves,    spinal 

cord,  spinal  nerves. 
Sympathetic  system. — Composition,  ganglia,  sympathetic 

nerves,  practical  application. 
Disorders ^^ 

IX.  CIRCULATION 

Blood. — Circulatory    apparatus,    course    of    the    blood, 
blood  supply  of  the  body,  principal  arteries  and  veins. 
Lymphatic  system. — Parts,  function. 
Practical    application,    disorders 42 

X.  RESPIRATION 

Definition,  stages,  parts,  purpose,  respiratory  apparatus, 
practical  application,  disorders 51 

XL  DIGESTIVE  APPARATUS 

Definition,  organs  of  digestion,  anatomy  of  each,  prac- 
tical  application 57 

XII.  PHYSIOLOGY  OF  DIGESTION 

Definition  of  digestion,  food  groups,  course  and  history 

of  each  group,  practical  application  and  suggestions       64 

XIII.  URINARY  ORGANS 

Structure,  function,  and  physiological  operation  of  each, 
practical  application,  disorders 68 

XIV.  MAMMARY  GLANDS 

Anatomy,  function,  products,  blood  supply,  nerve  supply, 
and  nerve  control,  practical  application,  disorders      .        72 

PATHOLOGY 
XV.  PATHOLOGY 

Hyperaemia  (congestion),  inflammation,  fever,  heat  pro- 
duction and  expenditure,  symptoms  of  fever,  results 
of  fever,  practical  application 77 

XVI.  PATHOLOGY  {Continued) 

Hemorrhage,  dropsy,  hypertrophy,  atrophy,  degenera- 
tions and  infiltrations,  collapse,  syncope,  death,  ne- 
crosis,   practical    application '•        83 


CONTENTS 


Xlll 


LECTURE 

XVII. 


XVIII. 


PAGE 


WOUNDS 


Healing,  and  development  of  new  blood  vessels. 
Healing  of  osseous,  cartilage,  and  nerve  tissues.     New 
tissue,  how  skin  recovers  a  surface 88 

WOUNDS  (Continued) 


Bad   treatment,   bleeding,   sewing,   bandaging,  washing, 
dry  treatment,  maggots,   practical   suggestions 


91 


CAUSE  AND  PREVENTION 
XIX.  CONTAGIUM 

The  individual  bacterium,  plagues  in  history,  dissem- 
ination, development  of  outbreaks,  body  entrance, 
method  of  injury,  resistance,  how  destroyed  in  nature, 
classification,  practical  suggestions 96 

XX.  DISINFECTION 

Purpose,  sources  of  infection,  thoroughness,  attendants, 
how  to  burn  a  carcass,  common  disinfectants, 
methods  of  disinfection 102 

XXI.  HEREDITY— AIR 

Theory  of  heredity  in  relation  to  disease,  in-and-in  breed- 
ing. 

Air  impurities,  relations  to  disease,  standards  of  purity, 
ventilation,  practical  application 106 

XXII.  VENTILATION 

Stable  air,  necessity,  unventilated  air,  natural  forces, 
air  currents,  outlets 109 

XXIII.  VENTILATION  {Continued) 

Stable  construction. — Space,  location,  stable  construc- 
tion for  ventilation,  ventilation,  amount  of  air  needed     114 

XXIV  FOOD  AND  WATER 

Food. — Excess,  deficiency,  bulk,  quality,  balance,  inter- 
vals, poisonous  foods. 
Water. — Excess,  deficiency,  parasites,  sewage,  intervals. 
Practical   application 119 


xiv  CONTENTS 


PARASITIC  DISEASES 

LKCTURE  PAGl 

XXV.  PAKASITISM 

Parasitism. — Sources,  how  nourished,  effect  on  host, 
general  prevention,  general  treatment,  practical  ap- 
plication. 

External  Parasites. — Lice,  flies,  ringworm,  sheep  ticks, 
ticks,  treatment  and  suggestions  for  each   ....     124 

XXVI.  SHEEP  SCAB 

Body  scab,  foot  scab,  head  scab,  general  prevention, 
general  symptoms,  treatment,  dips,  dipping,  disin- 
fection       130 

XXVII.  MANGE 

Horse  mange  and  cattle  mange,  cause,  symptoms,  treat- 
ment of  each 137 

XXVIII.  INTERNAL  PARASITES 

Bets,  roundworms,  tapeworms,  treatment  ......     141 

XXIX.       NODULE  DISEASE  OP  SHEEP 

General  history,  cause,  injury,  diagnosis,  treatment, 
prevention 145 

XXX.  STOMACH  WORM  (SHEEP) 

Parasite,  life  history,  symptoms,  treatment,  drenching 
sheep,  management   of   infected   flock,   prevention      .      149 

XXXI.    VERMINOUS   BRONCHITIS,   NASAL 
GRUB,  AND  CATARRH 

Verminous  bronchitis. — Cause,  life  history  of  parasites, 

symptoms,  treatment,  prevention. 
Nasal  grub. — Cause,  life  history,  symptoms,  treatment. 
Catarrh. — Simple    catarrh    defined,    causes,    prevention, 

treatment 153 

INFECTIOUS  DISEASES 
XXXII.     ACTINOMYCOSIS  (LUMPY  JAW) 

Description,  relation  to  public  health,  parts  involved, 
treatment 158 


CONTENTS  XV 

LECTURB  ""AGE 

XXXIII.  ANTHRAX 

History,  distribution,  susceptible  animals,  cause,  trans- 
mission, introduction  and  spread,  incubation,  symp- 
toms, post  mortem,  diagnosis,  vaccination  ....      163 

XXXIV.  SYMPTOMATIC  ANTHRAX 

Cause,  symptoms,  post  mortem,  prevention,  vaccination     167 

XXXV.  BACILLUS  NECROPHORUS  INFECTIONS 

Explanation,  cause,  infection,  foot  rot,  lip-and-leg  ul- 
ceration, canker  sore  mouth,  necrotic  stomatitis,  symp- 
toms, treatment,  management,  etc.,  for  each     .      .      .      170 

XXXVI.  FOOT-AND-MOUTH  DISEASE 

Definition,  symptoms,  similar  diseases,  dissemination, 
prevention,  treatment 177 

XXXVII.        HEMORRHAGIC  SEPTICEMIA 

Etiology,  history  and  development,  symptoms,  post  mor- 
tem, summary,  differential  diagnosis 180 

XXXVIII.  TEXAS  OR  TICK  FEVER 

Economic  importance,  causes,  trananission,  suscepti- 
bility, incubation,  symptoms,  post  mortem,  prognosis, 
treatment,  prevention,  tick  extermination,  vaccination     185 

XXXIX.  TUBERCULOSIS 

Prevalence,  cause,  modes  of  infection,  structures  af- 
fected, spiiptoms,  diagnosis,  treatment,  prevention, 
summary,  disposition  of  tuberculous  cattle,  accredited 
herd  plan 192 

XL.  TUBERCULIN  TEST  FOR  TUBERCULOSIS 

Tuberculin  effect  on  health,  accuracy,  thermal,  intra- 
dermal, and  ophthalmic  tests,  importance  to  breeders     198 

XLI.  GLANDERS 

Susceptible  animals,  causes,  incubation,  symptoms,  acute 
eases,  chronic  eases,  farcy,  diagnosis,  mallein  tests, 
prevention,   suggestions 203 


xvi  CONTENTS 

LECTURE  PAGE 

XLII.  HOG  CHOLERA 

Definition,  symptoms,  autopsy,  cause,  how  scattered, 
vaccination,  common  mistakes,   suggestions      .      .      .      208 

XLIII.  COMMON  MINOR  DISEASES  OF  SWINE 

Posterior  paralysis,  congestion  of  the  lungs,  constipa- 
tion, cause,  symptoms,  treatment  of  each,  drenching 
swine,  suggestions 215 

DIETETIC  DISEASES 
XLIV.  AZOTURIA 

Prevalence,  history,  parts  affected,  duration,  causes, 
symptoms,  prevention,  treatment,  prognosis       .      .      .      218 

XLV.  LYMPHANGITIS  (ELEPHANT  LEG) 

Cause,  symptoms,  prevention,  treatment,  prognosis   .      .      222 

XLVI.  LAMINITIS  (FOUNDER) 

Definition,  symptoms,  cause,  pathology,  termination, 
prevention,    treatment         224 

XLVII.  HEAVES 

Definition,  cause,  symptoms,  prevention,  post  mortem, 
treatment 227 

XLVIIL        HOVEN,  OR  BLOAT  (ACUTE 

TYMPANITES) 
Definition,  causes,   symptoms,   treatment,  prevention      .      230 

XLIX.  PARTURIENT  PARALYSIS  (MILK 

FEVER) 

Causes,   symptoms,   prevention,  treatment,  prognosis      .      233 

L.  CHOKE 

Explanation,  symptoms,  prevention,  treatment,  general 
suggestions 238 

MISCELLANEOUS  DISEASES 
LL  UNSOUNDNESS 

Unsoundness,  normal  condition,  ringbone,  sidebone, 
spavin,  splints,  curb,  bog  spavin,  open  joint,  hygromas, 
miscellaneous    unsoundness 241 


CONTENTS 


xvii 


LECTURE 

LII. 


PAGE 


UNSOUNDNESS  {Continued) 

Examination  at  rest,  in  motion,  examination  in  detail. 
Lameness. — Locating  lameness,  tests 249 


OBSTETRICS 

LIII.  OBSTETRICS 

Organs  described,  normal  periods  of  gestation. 
Accidents  of  pregnancy. — Sporadic  abortions,  infectious 
abortions,  symptoms,  results 254 

LIV.  OBSTETRICS  (Continued) 

Infectious  abortion. — Causes,  virus,  dissemination,  in- 
fection, results,  importance,  various  classes  of  stock, 
diagnosis,  prevention,  management  of  aborting  herd, 
disinfection,  medical  treatment,  vaccines,  calves     .      .      259 

LV.  OBSTETRICS  {Concluded) 

Accidents  of  pregnancy. — Eetention  of  fetus,  volvulus, 
or  twist. 

Accidents  of  parturition. — Infection,  inflammation  of 
the  uterus,  inversion  of  the  uterus,  retention  of  the 
afterbirth,  hemorrhage 264 

LVI.         DISORDERS  OF  THE  UDDER 

Garget. — Definition,  causes,  symptoms,  results,  preven- 
tion, treatment. 

Udder  diseases  and  accidents. — Injuries,  obstruction, 
warts,  eowpox,  etc 269 

LVII.  DIFFICULT  PARTURITION 

Difficult  parturition. — Nature's  plan,  normal  presenta- 
tions, causes  of  difficulty,  common  faulty  presenta- 
tions, aid,  suggestions,  operations 274 


MEDICINES 
LVIII.  COMMON  MEDICINES 

Common  measurements  and  weights,  giving  medicines, 
various  common  medicines  as  to  physiological  effects, 
doses  and  uses 280 


sviii  CONTEXTS 


LEC 


PAGE 


LIX.      COMMOX  MEDICIXES  (Continued) 

Various  common  medicines,  as  to  physiological  effects. 
doses  and  uses --^ 

LX.     COMMOX  MEDICIXES   ^Concluded) 

Various  common  medicines,  physiological  effects,  doses 
and   uses 287 

MINOR  SURGICAL  OPERATIONS 
LXI.     MIXOR  SUEGICAL  OPERATIOXS 

Castration,  various  kinds  of  stock-  Dehorning,  by  caus- 
tic, shears,  saw.  Docking.  Draining  abscess.  Semoc- 
ing  varts.    lapping  for  hloot 291 


ILLUSTRATIONS 


PAGE 

T    Skeleton.    B.A.I ^«^'"^  ^ 

o 

2.  Horse  Skull.     Chcuieau 

3.  Teeth  of  Horse  6  Years  Old  (Lower  Jaw) ^ 

4.  Teeth  of  Horse  8  Years  Old  (Upper  Jaw).    Oarke      ....  4 

5.  Teeth  of  Horse  20  Years  Old  (Lower  Jaw).     Clarke     ....  5 

6.  Grinding  Surface  of  Molars.     Euidekoper ^ 

7.  Typical  Cervical  Vertebra.     Chauveau ' 

8.  Typical  Dorsal  Vertebra   (Front  View).     Chauveau      ....  8 

9.  Typical  Lumbar  Vertebra  (Front  View).     Cliauveau     ....  8 

10.  Lateral  View  of  the  Sacrum.    Chauveau ^ 

11.  Anterior  Limb  of  the  Horse.    Chauveau H 

12.  Posterior  Limb  of  the  Horse.    Chauveau 1-^ 

13.  Bones  of  the  Horse 's  Foot.     Chauveau 19 

14.  The  Hoof.     Chauveau 

15.  The  Hoof  Matrix.     Chauveau -^ 

16.  Voluntary  Muscle.     BeynoJds ^^ 

17.  Muscle  Fibers.    Hewes ^^ 

18.  The  Cerebrospinal  Nervous  System.    Magnin 33 

19.  Neuron ^^ 

20.  Medullated  Nerve  Fibers ^^ 

21.  Spinal  Cord  and  Brain  in  Diagram.    Beynolds 36 

22.  Relation  of  the  Sympathetic  and  Cerebrospinal  Systems,  Partly 

Diagrammatic.    Chauveau 38 

23.  Circulation,  General  View.    Magnin 43 

24.  Circulation,  Diagrammatic.    No.  1,  BeynoJds;  No.  2,  after  Overton  44 

25.  CapiUary  Circulation.     Eddy •*5 

26.  The  Lymphatic  System   (Human).     Eddy 48 

27.  A  Lymph  Node.    Eddy ^^ 

28.  Respiration  in  Diagram.     Eeynolds 52 

29.  Stomach  of  the  Horse  (External  and  Internal  Views).     Chauveau  58 

30.  Stomach  of  the  Cow.    After  Chauveau 59 

31.  Section  of  Horse  Kidney.    Chauveau 68 

32.  Urinary  Apparatus  in  Diagram.    Eeynolds 69 

33.  One  Quarter  and  Teat  of  the  Cow 's  Udder.    Tlianhoffer    ...  72 

xix 


XX  ILLUSTRATIONS 

FIO.  PAGE 

34.  Milk  Vesicles  and  Outlet  Ducts.    Chauvecm 73 

35.  Badly  Treated  Wire  Wound.    Reynolds 91 

36.  General  Groups  of  Bacteria.     Reynolds 99 

37.  Ventilation.    Paige 109 

38.  Ventilation.    Paige 112 

39.  Ventilation.    Paige 115 

40.  Cupola  A^entilation.     Paige 116 

41.  Ventilation.    Paige 116 

42.  Cattle  Louse  (Female).     Neuman     .          126 

43.  Sheep  Tick  and  Enlarged  Proboscis.    Neuman 128 

44.  Plain  Case  of  Sheep  Scab 131 

45.  Sheep  Scab  Mites.    Curtice,  Lugger,  Pettit 132 

46.  Mange  Mite.    Neuman 137 

47.  Horse  Botfly  and  Larva.     Neuman 141 

48.  Horse  Bots  and  Botfly.    B.  A.  I 142 

49.  Common  Tapeworm  of  Sheep.     Curtice 144 

50.  Nodule  Disease.     Reynolds 146 

51.  Stomach  Worm  on  Tip  of  Grass  Blade.     Ransom 149 

52.  Sheep  Gadfly.     Brauer 155 

53.  Actinomycosis  (Lumpy  Jaw).    Reynolds 159 

54.  Actinomycosis.     Reynolds 160 

55.  Actinomycosis.     Reynolds 160 

56.  Bacterium  Anthracis.     Reynolds 163 

57.  Bacillus  Necrophorus.     B.  A.  I ....  170 

58.  Foot  Eot  (Sheep).     Williams 171 

59.  Lip  and  Leg  Ulceration.    B.  A.  1 175 

60.  Hemorrhagic  Septicaemia.    Reynolds 181 

61.  Hemorrhagic  Septicaemia.    Reynolds 182 

62.  Hemorrhagic  Septicaemia.     Reynolds 183 

63.  Hemorrhagic  Septicaemia.     Reynolds 184 

64.  Texas  Fever  Tick.    Pettit 185 

65.  Bovine   Tuberculosis.     Reynolds 192 

66.  Bovine   Tuberculosis.     Reynolds 193 

67.  Bovine   Tuberculosis.     Reynolds 194 

68.  Bovine  Tuberculosis.     Reynolds 195 

69.  Glanders  (Farcy).    Reynolds 204 

70.  Glanders  (Farcy).    Reynolds 205 

71.  Glanders  (Farcy).    Reynolds     . 206 

72.  Hog  Cholera.    Reynolds 209 

73.  Hog  Cholera.    Reynolds 210 


ILLUSTRATIONS  xxi 

FIG.  f^«^ 

74.  Hog  Cholera.    Eeynolchi 211 

75.  Hog  Cholera.    Hetjuolds 212 

76.  Foundercil  Hoof.     B.  A.  1 225 

77.  Showing  Whore  to  Tap  for  Bloat.     Beynolds 230 

78.  Trocar  and  Cannula 231 

79.  Parturient  Paralysis.     Reynolds 233 

80.  Parturient  Paralysis.     Ecynolds 234 

81.  Parturient  Paralysis.     Beynolds 235 

82.  Wire  for  Relieving  Choke.    Beynolds 239 

83.  Ringbones.    Beynolds 243 

84.  Sidebones.     Beynolds 243 

85.  Spavins  (Two  Types).     Reynolds 244 

86.  Navicular  Disease.     Beynolds 247 

87.  Generative  Organs  of  the  Mare.     Fleming 254 

88.  Fetus    and    Fetal    ^^lenibranes    of    the    Cow    at    Mid-pregnancy. 

Fleming 255 

89.  Bovine  Cotyledons.     Fleming 256 

90.  Presentations.    B.  A.  1 275 

91.  Holding  Horse's  Head  for  Drenching.    Reynolds 281 

92.  Throwing  Cattle.     Beynolds 291 

93.  Restraint  for  Castration.     White 292 

94.  General  View  of  Scrotum  and  Sheath.     White 292 

95.  A  Good  Type  of  Emasculator.    White 293 


VETERINARY   STUDIES 


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VETERINARY   STUDIES 


LECTURE  I 

ANATOMY 

Anatomy  is  the  science  which  treats  of  forms,  structures, 
and  relations  to  body  organs.  These  org-ans  are  divided 
for  study  into  groups  as  follows:  bones,  muscles,  joints, 
nervous  system,  circulatory  apparatus,  respiratory  apparatus, 
urinary  apparatus,  digestive  apparatus,  and  reproductive  ap- 
paratus. 

Osteology,  Bones 

Kinds.— Bones  are  classified  as  long,  short,  flat,  and  irregular. 

Long  hones  are  more  or  less  elongated  in  form  and  have  a  mar- 
row-filled canal  in  the  shaft,  example— humerus,  femur,  radius, 
and  tibia.  They  are  used  in  the  legs  as  columns  of  support  and 
for  levers  pulled  by  muscles  to  produce  motion. 

Short  bones  are  usually  short  in  form,  and  have  no  medullary 
canal.  Examples  of  this  class  are  carpals  and  tarsals.  They  are 
used,  for  example,  in  the  knee  and  hock  where  complicated  artic- 
ulation is  needed  with  ability  to  stand  pressure. 

Flat  hones,  like  those  of  the  skull  and  the  ribs,  consist  of  two 
plates  of  hard  bone  tissue  connected  by  porous  bone.  They  are 
used  to  enclose  and  protect  vital  organs  and  to  provide  muscle 
anchorage. 

Irregular  hones  are  usually  found  in  the  median  line  of  the 
body ;  example,  vertebrae.  These  are  adapted  for  weight  support 
and  muscle  anchorage. 

Peculiarities. — Terms  used  in  describing  and  recognizing  bones 
are:  elevations,  depressions,  borders,  surfaces,  angles,  and  ex- 
tremities. 

Development. — Bones  develop  around  centers  of  ossification 
(bone  formation)  either  in  cartilage  or  membrane.  Long  bones 
develop  from  cartilage;  the  flat  bones  develop  from  membrane. 

1 


2  VETERINARY  STUDIES 

Bones  grow  in  diameter  by  the  production  of  new  bone  cells  at 
the  inner  surface  of  the  periosteum.  They  grow  in  length  by  the 
development  of  bone  cells  in  a  cartilage  matrix  between  centers 
of  bone  formation  in  the  shaft  and  extremities  of  the  bone.  A 
long  bone,  for  instance,  may  have  three  centers  of  ossification, 
one  in  the  shaft  and  one  in  each  end,  with  a  layer  of  this  cartilage 
matrix  in  the  end  between  the  centers  of  ossification.  Bone  cells 
in  the  lacunas  (spaces)  throughout  the  substances  of  the  bone, 
prepare  and  deposit  lime  salts  and  other  material. 


Fig.  2. — Horse's  Skull.     (Chauveau.) 

1,  Premaxillary  bone;  2,  upper  incisors;  3,  upper  canine  teeth;  4,  supe- 
rior maxillary  bone;  7,  nasal  bones;  8,  lachrymal  bone;  11,  malar  bone; 
12,  upper  molar  teeth;  13,  frontal  bone;  15,  temporal  bone;  16,  parietal 
bone;  17,  occipital;  20,  styloid  processes;  24,  parietal  crest;  25,  inferior 
maxilla;  26,  inferior  molars;  28,  inferior  canine  teeth;  29,  inferior  incisor 
teeth. 

Structure  and  composition. — In  a  general  way,  bones  consist 
of  surface  plates  of  fine  texture,  hard  bone  with  porous  bone 
inside  of  this.  In  the  short,  flat  and  irregular  bones,  this  porous 
bone  makes  up  the  whole  interior.  A  long  bone  consists  of  two 
enlarged  extremities,  composed  of  porous  bone,  and  a  shaft  hav- 
ing a  surface  of  hard  bone,  covered  on  the  inside  with  bone  of  the 
porous  texture.  Tliis  porous  bone  then  surrounds  the  medullary 
canal  which  is  characteristic  of  long  bones.  A  thin  layer  of 
cartilage  covers  all  articular  surfaces.  The  porous  bone  is  filled 
with  red  marrow  and  the  medullary  canal  is  filled  with  yellowish 
marrow. 

Except  at  the  articular  surfaces,  bones  are  covered  by  a  thin 
tough  membrane,  called  periosteum.    This  is  a  matrix  or  mother 


ANATOMY 


membrane  and  plays  a  most  important  pan  in  the  growth  and 
nourishment,  and  repair  in  case  of  injury. 

The  head  contains  26  ^  bones,  divided  into  two  groups  as 
follows:  cranium  9,  fa^c  n.  Cramum  9:  occipital  1,  frontal  2, 
parietal  2,  temporal  2,  ethmoid  1,  sphenoid  1.  Face  17:  supe- 
rior maxillary,  2  ;  inferior  maxillary,  1 ;  premaxillary,  2 ;  palate, 
2 ;  malar,  2 ;  lachrymal,  2 ;  nasal,  2 ;  vomer,  1 ;  inferior  tur- 
binated, 2  ;  hyoid  1. 

Teeth. — Mares  have  on  each  jaw :  6  incisors  and  12  molars, 
or  in  all  18.  Geldings  and  stallions  have,  in  addition,  2  canines 
or  tushes,  making  20  teeth  on  each  jaw.  All  the  incisors  and 
the  first  three  molars  are  temporarv'^  and  are  replaced.  The  last 
three  come  in  as  permanent  teeth,  according  to  the  following 
table. 

Dentition  op  Horses — (Chauveau) 


Kind 

Number 

When   Appear 

When  Replaced 

r 

Center    

Middle    

Corner    

Birth    

21/2  years. 
31/2  yeai-s. 
4I/2  years. 

Incisors i 

4  to  6  weeks 

6  to  9  months   .... 

4  to  5  years    

Birth 

Canines   

1st    

21/2  years. 
21/2  years. 
3y2  years. 

2d 

Birth    

Molars  - 

3d    

Birth    

4th   

10  to  12  months  .. 

2  years    

4  to  5  years   

5th   

()th   

Age  of  horses  by  the  teeth. — Tell  by  shedding  and  appear- 
ance of  the  teeth  up  to  -4  years,  according  to  table.  Cups  wear 
out  of  center  pair  of  incisors  of  lower  jaw  at  about  6  years ;  cups 
wear  out  of  middle  pair  of  incisors  at  about  7  years;  and  cups 
wear  out  of  corner  incisors  at  about  8.  Quality  of  the  teeth, 
kind  of  food,  and  the  way  the  teeth  fit  together  to  be  considered. 
They  may  wear  very  unevenly  and  be  very  deceptive.  The 
upper  incisors  are  much  less  reliable  as  to  disappearance  of  cups 
than  are  the  lower. 

Cattle  have  8  incisors  on  tlie  lower  jaw  and  none  on  the 
upper.  Their  molars  are  like  those  of  horses  in  number,  and 
the  first  three  are  also  temporary.     The  calf  has  the  two  center 


'  Sisson  recognizes:    pteryjjoids,  2;  turbinated  4  (2  dorsal  and  2  ventral), 
and  an  interparietal,  making  10  for  the  cranium  and  21  for  the  face. 


4  VETERINARY  STUDIES 

pairs  of  incisors  at  about  birth;  the  next  pair  at  about  14  days, 
and  the  corner  pair  by  about  3  weeks.  Thus  the  calf  has  a 
full  mouth  of  temporary'  incisors  at  about  one  month. 


Fig.  3. — Six  Years,  Lower  Jaw. 

The  incisors  are  replaced  in  pairs  beginning  with  the  center 
at  11/2,  21/2,  31/2  a»d  the  corner  pair  at  41/2  years. 

In  young  horses,  the  grinding  surfaces  of  the  incisors  are  wide 
from  side  to  side.    At  about  13  to  15  years  these  surfaces  are  as 


Fig.    4. — Eight   Years,    Upper    Jaw. 
2Vo/e. — Figures  4   and   5   are   drawn   on   different  scales. 

wide  from  before  back  as  from  side  to  side.    In  very  old  horses, 
this  surface  is  narrow  from  side  to  side. 

The  incisors  of  young  horses  extend  at  nearly  right  angles  from 


ANATOMY  5 

the  end  of  the  maxillary  bones ;  those  of  very  old  horses  meet  at 
an  acute  angle,  and  the  teeth  appear  to  project  forward  from  the 
ends  of  the  jaws. 

Original  observations. — The  student  should  make  original  ob- 
servations, recording  freely  by  notes  and  drawings.    He  should 


Tig.  5. — Twenty  Years,  Lower  Jaw. 

study  the  part  played  by  individual  bones  or  groups  of  bones  in 
determining  the  size  and  shape  of  the  head. 

Study,  e.g.,  the  nasal,  frontal,  superior  maxillary,  and  inferior 
maxillary  bones.  Note  what  relation  they  bear  to  shape  of  nose, 
width  between  the  eyes,  "coarseness"  of  the  head,  and  width 
between  bones  of  the  lower  jaw. 


B 


Fig.  G. — Grinding  Surfaces  of  Molars. 

Horse  six  to  seven  years  old.     A,  right-hand   superior   molars;    B,  left- 
hand    inferior   molars. 

Spend  as  much  time  as  possible  in  practice  at  estimating 
horses'  ages  by  their  teeth.  Note  especially  temporary  and  per- 
manent teeth  present,  "cups,"  and  shape  of  wearing  surface. 

Common  disorders. — Among  the  more  common  diseases  and 
abnormal  conditions  of  the  bones  of  the  head  and  the  teeth  are: 


6  VETERINARY  STUDIES 

actinomycosis,  caused  by  a  fungus  and  characterized  by  enlarge- 
ment and  destruction  of  the  bones  of  the  upper  or  lower  jaw 
especially.  Big  head  (osteoporosis),  which  affects  the  bones  of 
the  horse,  usually  including  the  head  bones.  The  bones  become 
very  light  in  weight  and  very  fragile. 

Common  disorders  of  the  teeth  are:  variations  from  normal 
number  more  or  less ;  improper  fit,  parrot  mouth  where  the 
upper  incisors  overhang  the  lower ;  undue  relative  width  of  the 
upper  jaw,  leading  to  uneven  wear,  ragged  edges,  and  injury 
to  cheeks  or  tongue;  caries  (decay) ;  and  toothache  with  abscess 
at  the  root. 


LECTURE  II 
OSTEOLOGY 

Spinal  column.— This  consists  of  about  55  pieces,  called  ver- 
tebrie.  There  are  7  cervical,  18  dorsal,  6  lumbar,  5  sacral,  15 
to  21  coccygeal. 

There  are  certain  general  characteristics  possessed  by  all  ver- 
tebra, regardless  of  location  in  the  spinal  column ;  for  instance, 
each  vertebra  has  a  body,  arch,  and  spinal  canal. 

The  hodij,  convex  in  front  and  concave  behind,  is  below  the 
spinal  canal.  The  head  of  the  body  of  each  vertebra  is  rounded 
and  fits  perfectly  into  the  cavity  of  the  rear  end  of  the  preced- 
ing vertebra.  Between  each  pair  is  considerable  cartilage,  which 
serves  the  purpose  of  an  elastic  pad. 

The  arch  incloses  the  sides  and  top  of  the  spinal  canal.  (1) 
The  transverse  processes  are  the  portions  which  project  hori- 
zontally on  each  side  from  the  arch. 
(2)  The  superior  process  projects  up- 
ward from  the  top  of  the  arch.  (3) 
The  articular  processes  are  four  in 
number :  two  in  front,  and  two  behind. 
The  former  articulate  with  the  rear 
articular  processes  of  the  preceding  y\g.  7.— Typical  Ceevical 
vertebra,  and  the  latter  with  the  front  Vertebra. 

processes  of  the  succeeding.  ^-  Head  of  the  body;  B, 

.  mi       p  1        transverse   process;    C,   ar- 

CervicaJ  vertebrae.— The  framework     ticuiar   process;    B,  supe- 
consists    of    7    cervical    vertebne,    all     rior  spiuous  process, 
agreeing  in  certain  general  characters. 

The  body  is  long,  thick,  and  has  an  inferior  spine  projecting 
downward  from  its  under  surface.  The  superior  processes  are 
long  from  before  to  behind,  and  together  form  a  long  rough  line. 
The  transverse  processes  are  also  long  from  before  to  behind.  In 
these  characteristics  the  cervical  vertebrae  differ  radically  from 
the  others. 

Special  cervical  vertchrcv. — There  are  certain  cervical  verte- 

7 


8 


VETERINARY  STUDIES 


Fig.    8. — Typical    Dorsal 
Vertebra,  Front  View. 

1,  Head  of  the  body;  2, 
superior  spinous  process ; 
3,  transverse  process. 


brffi  which   have  marked   individual   peculiarities.      The   atlas, 
immediately  supporting  the  head,  has  a  small  thin  body  with  no 

head,  but  instead,  two  surfaces  for 
articulating  with  the  occipital  bone. 
The  axis  is  long,  and  has,  in  place  of 
the  head,  a  peculiar  projection  known 
as  ''odontoid  process."  This  process 
is  shaped  somewhat  like  a  tooth.  Hence 
the  name.  The  superior  process  is 
long  from  front  to  rear.  The  seventh 
cervical  vertebra  has  a  long  superior 
process,  somewhat  resembling  those  of 
dorsal  vertebrae.  It  also  presents  a 
small  articular  surface  for  articulation 
with  the  head  of  the  first  rib. 
Dorsal  vertebrae. — These  are  located  in  the  back,  and  are  18 
in  number.  They  also  have  certain  general  characteristics.  The 
body  is  short.  There  are  four  articular  cavities,  two  in  front 
and  two  behind  for  the  heads  of  the 
ribs.  Superior  processes  are  long  and 
flat  frpm  side  to  side,  transverse  proc- 
esses short  and  small.  None  of  the 
dorsal  vertebra  differ  very  markedly 
from  this  general  type. 

Lumbar  vertebrae. — These  make  up 
the   framework   of   the   loin.      In   gen- 
eral   the    body    is    longer    and    wider 
than  the  dorsal.     The  superior  processes  are  also  shorter.     The 
transverse  processes  are  long,  flat,  and  thin. 

Sacrum. — This  constitutes  the  croup. 
It  consists  of  five  pieces,  united  in  the 
adult.  It  articulates  with  the  last 
lumbar  vertebra  in  front,  with  the  first 
coccygeal  vertebra  behind,  and  with 
the  pelvis  on  each  side.  This  portion 
of  the  spinal  column  is  triangular, 
with  the  base  forward. 

Coccygeal  vertebrae. — These  are  15 
to  21  in  number,  and  located  in  the  tail.  The  spinal  canal  is 
developed  in  the  first  three  or  four.  The  first  one  is  occasionally 
united  to  the  sacrum. 


Fig.   9. — Typical  Lumbar 
Vertebra,  Front  View. 

1,  Body;  2,  head;  3,  su- 
perior spinous  process;  4, 
transverse  process. 


Fig.  10. — Lateral  View  op 
the  Sacrum. 

1,  Spinal  canal,  anterior 
portion;  3,  superior  spinous 
processes. 


OSTEOLOGY  9 

The  sternum. — This  is  located  in  the  front  and  lower  portion 
of  the  eliest,  and  extends  from  before  to  behind.  It  consists  of 
six  or  seven  pieces  of  cartilaginous  bone  and  has  distinct  pro- 
longations of  cartilage  from  both  the  front  and  rear  ends.  On 
each  side  are  articular  surfaces  for  the  first  eight  ribs.  The 
sternum  is  commonly  called  the  breast  bone. 

Ribs.— These  usually  number  18  pairs,  and  are  described  as 
the  first,  second,  third,  etc.,  beginning  with  the  front  pair. 
They  all  articulate  above  with  the  dorsal  vertebrae;  the  lower 
ends  of  the  first  eight  articulate  with  the  sternum  by  means  of 
cartilages.  The  remaining  ten  connect  with  the  sternum  by 
means  of  long  cartilages,  each  of  which  rests  against  the  pre- 
ceding one.  The  ninth,  or  first  asternal,  rib  is  united  rather 
closely  to  the  eighth,  which  articulates  with  the  sternum. 

The  shaft  shows  external  convex  and  internal  concave  sur- 
faces and  two  borders :  anterior  or  front,  and  posterior  or  rear. 
The  superior  or  upper  extremity  shows  a  head  and  a  small  pro- 
jection, the  tuberosity.  These  articulate  with  the  dorsal  ver- 
tebra? as  already  explained.  Function  of  the  ribs  is  to  form  a 
supporting  and  movable  wall  for  the  chest,  protecting  the  soft 
organs  and  performing  a  very  important  function  in  opening 
the  chest   for  respiration. 

Practical  application. — The  student  should  now  study,  for 
himself,  the  part  played  by  each  group  of  vertebrae  in  determin- 
ing the  conformation  of  its  region.  Take,  e.g.  the  cervical,  dor- 
sal, lumbar,  and  sacral  groups,  and  note  what  relation  they  bear 
to  length  of  neck,  height  and  shape  of  withers  and  length  of 
back,  width  and  length  of  loin,  length  and  slope  of  the  croup. 
The  student  should  also  study  the  influence  of  shape  of  rib 
upon  width  of  back  and  shape  of  sides.  Record  fully  by  notes 
and  drawings. 

Common  disorders. — Domestic  animals  arc  subject  to  many 
disorch'rs  of  this  region  but  few  of  these  affect  the  vertebra? 
especially.  There  are  occasional  fractures  and  dislocations. 
Tuberculosis,  osteoporosis,  etc.,  may  affect  these  bones  as  well 
as  others.  Sometimes  adjacent  vertebrtp  unite  by  a  bone-form- 
ing process  following  inflammation  (ostitis)  most  frequently 
resulting  from  injury. 


LECTURE  III 
FRONT  LIMB 

This  limb  is  composed  of  20  bones,  and  includes  the  shoulder, 
arm,  forearm,  and  foot. 

Shoulder. — The  shoulder  contains  but  one  bone,  the  scapula, 
or  shoulder  blade.  This  is  triangular  and  situated  at  the 
front  portion  of  the  chest  wall.  Its  direction  is  downward 
and  forward,  and  it  articulates  below  with  the  head  of  the 
humerus,  or  arm  bone.  The  inner  surface  is  somewhat  concave. 
The  external  surface  is  divided  into  two  portions  by  a  long 
ridge  which  extends  lengthwise  of  the  bone.  The  upper  portion 
is  flat  and  thin. 

Arm. — The  arm  contains  a  single  long  bone,  the  humerus.  Its 
upper  end  articulates  with  the  scapula,  and  the  lower  end  with 
the  ulna  and  radius.  It  offers  for  description  a  shaft  and  upper 
and  lower  extremities.  A  peculiar  feature  of  the  shaft  is  a  sort 
of  furrow,  which  twists  partially  around  the  bone  and  is  known 
in  anatomy  as  the  furrow  of  torsion.  The  superior  extremity 
shows  a  rounded  head,  which  is  fitted  for  articulation  with  a 
corresponding  cavity  of  the  scapula,  and  the  bicipital  groove 
in  front,  which  holds  the  tendon  of  the  biceps  muscle. 

The  inferior  extremity  is  flattened.  Its  articular  surface  has 
two  condyles,  separated  by  a  shallow  groove,  fitting  it  for  artic- 
ulation with  the  radius.  This  extremity  shows,  on  its  posterior 
surface,  a  deep  fossa  which  fits  the  peculiar  articular  surface 
of  the  ulna  and  gives  a  perfect  hinge  joint  that  is  not  easily 
dislocated. 

Forearm. — The  forearm  contains  two  bones,  the  radius  and 
ulna.  In  the  horse  and  cow  these  are  firmly  united.  The  radius 
belongs  to  the  group  classified  as  long  bones,  and  articulates 
with  the  humerus  above  and  the  carpal  bones  below.  Its  an- 
terior surface  is  convex  and  smooth ;  its  posterior  surface,  con- 
cave. The  ulna  is  also  a  long  bone,  located  just  back  of  the 
radius.  The  shaft  is  triangular.  The  upper  extremity  shows  a 
marked  enlargement  which  is  useful  for  attachment  of  muscles 

10 


FRONT  LIMB 


11 


and  gives  leverage.  It  contains  a  deep  notch  Avith  a  large  beak 
at  the  top  for  articulation  with  the  humerus.  The  inferior  por- 
tion of  this  bone  is  slender  and  more 
or  less  pointed,  containing  at  its  ex- 
tremity a  small  knob. 

Foot. — The  foot  includes  7  carpals, 
3  metacarpals,  2  sesamoids,  3  pha- 
langes, and  1  navicular. 

The  carpals  consist  of  seven  small, 
short  bones,  and  with  the  articulation 
of  the  carpals  to  the  radius  above, 
and  the  metacarpals  below,  make  up 
what  is  commonly  known  as  the  knee 
joint. 

The  metacarpals  are  located  in 
what  is  known  as  the  region  of  the 
cannon.  They  are  three  in  number  :  a 
large  one  in  the  middle,  which  is  long 
and  more  or  less  cylindrical ;  and  one 
rudimentary  metacarpal  on  each  side. 
These  together  articulate  above  with 
the  carpals,  and  the  large  one  below 
with  the  first  phalanx  and  the  sesa- 
moids. The  small  metacarpals  are 
commonly  known  as  splint  bones. 

The  first  phalanx  is  commonly 
known  as  the  pastern  bone.  It  is  the 
shortest  bone  in  the  body  that  is 
classified  as  a  long  bone.  The  shaft 
shows  an  anterior  convex  surface  and 
a  posterior  surface  which  is  flattened 
and  rough.  The  upper  extremity  is 
marked  by  two  shallow  cavities,  sepa- 
rated by  a  median  groove  and  fitted 
for  articulation  with  the  two  convex 
surfaces  and  the  median  ridge  w'hich 
mark  the  inferior  extremity  of  the 
large  metacarpal.  The  lower  extrem- 
ity has  two  convex  articular  surfaces  separated  by  a  median 
groove. 

The  sesamoids  are  two  small,  somewhat  triangular,  and  ir- 


FiG.  n. — Anterior  Limb  of 
THE  Horse. 

0,  Scapula;  H,  humerus; 
A,  radius;  U,  ulna;  C,  car- 
pals; M,  metacarpals;  S, 
sesamoids;   P,  phalanges. 


12  VETERINARY  STUDIES 

regular  bones,  placed  side  by  side  just  back  of  the  upper  part 
of  the  pastern  bone.  These  articulate  with  the  large  metacarpal. 
They  are  side  by  side  and  together  form  a  groove  for  the  flexor 
tendons. 

The  second  phalanx,  or  coronet  bone,  is  short  and  somewhat 
square  in  form.  It  articulates  with  the  first  phalanx  above,  and 
the  third  phalanx  and  navicular  below.  The  upper  and  lower 
extremities  of  this  bone  resemble  the  upper  and  lower  extremi- 
ties of  the  first  phalanx.  About  half  of  this  bone  is  below  the 
crown  of  the  hoof. 

The  third  phalanx,  or  pedal  bone,  is  pyramidal  in  shape  and 
irregular.  Its  superior  face  shows  two  shallow  cavities  separated 
by  a  median  ridge  fitted  for  articulation  with  the  second  pha- 
lanx. The  anterior  face  is  convex  and  quite  rough.  The  in- 
ferior surface  is  the  one  on  which  the  foot  rests.  It  is  called 
the  sole.  The  superior  border  of  the  anterior  face  has  quite  a 
projection  which  is  especially  fitted  for  the  insertion  of  a  ten- 
don. This  is  technically  known  as  the  pyramidal  process.  The 
lower  portion  of  this  bone  is  continued  outward  and  backward 
on  each  side  into  what  is  known  as  the  wing. 

The  navicular  hone  is  located  just  back  of  the  upper  part  of 
the  third  phalanx.  It  is  long  and  narrow,  and  placed  trans- 
versely. Its  anterior  surface  articulates  with  the  third  phalanx. 
Its  posterior  surface  is  covered  with  cartilage  and  forms  a  glid- 
ing surface  for  the  tendon  of  the  deep  flexor  muscle  which  passes 
over  this  bone  to  its  attachment  on  the  sole  or  inferior  surface 
of  the  third  phalanx. 

Practical  application. — Note  how  the  length  and  slope  of  the 
scapula  affects  the  type  of  shoulder,  gait  and  speed;  how  the 
length  and  slope  of  the  humerus  affects  the  type  of  arm  and  the 
gait.  The  cow  and  hog,  for  instance,  have  a  comparatively 
horizontal  humerus.  Note  the  effect  of  length  of  radius  and 
principal  metacarpal  on  conformation  of  the  limb  and  the  rela- 
tive length  of  these  two  segments.  Note  effect  of  the  first  and 
second  phalanges  on  the  relative  length  and  slope  of  the  pastern, 
giving  a  springy  pastern  or  a  short,  upright,  stilty  one.  Which 
horse  interferes,  the  one  with  the  long  pastern  toeing  out  or  the 
pigeon  toed  horse? 

Disorders  of  the  bones  on  the  front  limb  are  numerous.  The 
scapula,  radius  and  ulna  are  all  liable  to  fracture,  usually  as 
the  result  of  a  kick.     The  carpal  bones  are  subject  to  a  disease 


FRONT  LIMB  13 

called  knee  spavin,  a  bony  enlarj^ement  especially  on  the  inner 
side  of  the  knee.  The  metacarpal  is  subject  to  fracture  and 
splint,  the  latter  a  bony  enlargement  resulting  from  injury  and 
inflammation  and  producing  temporary  lameness  and  an  un- 
soundness. The  principal  metacarpal  is  a  common  seat  of  frac- 
ture and  is  a  rather  favorable  place  so  far  as  treatment  and 
recovery  are  concerned.  The  first  and  second  phalanges  are 
subject  to  fracture  and  ringbone,  the  latter  a  bony  enlargement 
due  to  inflammation  produced  by  injury,  and  to  heredity.  This 
causes  serious  unsoundness  and  often  permanent  lameness. 
Fracture  of  the  first  phalanx  is  not  uncommon.  Both  the  first 
and  second  phalanges  are  often  injured  in  barb  wire  accidents. 
The  third  is  subject  to  sidebone,  i.e.,  a  bony  enlargement  having 
about  the  same  causes  and  results  as  ringbone.  The  sole  of  the 
third  phalanx  is  subject  to  common  and  serious  injury  by  punc- 
ture through  the  sole.  The  navicular  bone  is  subject  to  injury 
from  puncture  resulting  in  inflammation  of  this  bone  and  to 
one  form  of  a  rather  common  disease  of  roadsters  known  as 
navicular  disease. 


LECTURE  IV 
POSTERIOR  LIMB 

The  posterior  limb  contains  20  bones,  and  is  divided  for  study 
into  pelvis,  thigh,  leg^,  and  foot. 

Pelvis. — The  pelvis  is  divided  into  two  halves,  each  half  being 
composed  of  three  bones  closely  united.  These  are:  (a)  the 
ilium,  the  external  angle  of  which  forms  the  prominence  of  the 
hip.  Its  internal  angle  articulates  with  the  sacral  vertebrae  at 
the  highest  point  of  the  croup.  Its  shaft  articulates  at  the 
cotyloid  cavity  with  the  ischium  and  pubis.  The  three  bones  of 
the  pelvis  form  at  this  point  the  cotyloid  cavity  into  which  fits 
the  head  of  the  humerus  at  the  hip  joint.  (6)  The  ischium 
forms  the  posterior  portion  of  the  floor  of  the  pelvic  cavity 
through  which  the  young  must  pass  at  birth.  It  articulates  at 
the  cotyloid  cavity  with  the  two  other  bones  of  the  pelvis.  Its 
posterior  angle  forms  the  prominence  commonly  known  as  the 
pin  bone,  (c)  The  pubis  forms  the  front  part  of  the  floor  of  the 
pelvic  cavity  and  articulates  with  the  ilium  and  ischium  at  the 
cotyloid  cavity.  To  the  breeder,  the  pelvis  is  for  obvious  rea- 
sons, a  most  important  part.  These  bones  are  distinct  in  early 
life,  but  become  united  as  the  animal  grows  older.  The  two 
halves  of  the  pelvis  bound  the  nelvic  cavity,  w'hich  contains  the 
rectum,  bladder,  and  sexual  organs.  Each  half  of  the  pelvis 
articulates  with  the  sacrum  at  the  croup. 

Thigh. — One  bone  only,  the  femur,  is  contained  in  the  thigh. 
This  bone  articulates  above  with  the  pelvis  and  below  with  the 
larger  of  the  two  leg  bones,  the  tibia,  and  with  the  patella.  The 
femur  belongs  to  the  group  which  we  have  classified  as  long 
bones,  and  is  the  heaviest  and  strongest  bone  in  the  body.  This 
bone  offers  for  study  a  shaft  and  upper  and  lower  extremities. 
The  shaft  shows  four  faces, — external,  internal,  and  anterior, 
w^hich  are  smooth  and  convex,  and  a  posterior  face  which  is 
rough  and  irregular  on  the  surface.  On  the  upper  extremity  we 
find  a  smooth  rounded  head  which  articulates  with  a  deep  cavity 
in  the  pelvic  bone  above.     On  the  external  side  and  projecting 

14 


POSTERIOR  LIMB 


15 


above  the  head  is  a  large  elevation  or  bony  prominence  known 
as  the  external,  or  great,  trochanter,  which  gives  attachment  and 
leverage  to  powerfnl  muscles  of  the 
hip.  Below  this  are  two  smaller 
trochanters  which  give  attachment 
to  other  muscles  of  this  region. 
The  inferior  extremity  is  somewhat 
flat  from  side  to  side  and  is  formed 
by  two  rounded  surfaces  which 
are  called  condyles.  These  are  sep- 
arated by  a  deep  groove  known  as 
the  trochlea  and  resemble  the  lips 
and  groove  of  a  pulley,  thus  fitting 
the  inferior  extremity  for  its  pecu- 
liar articulations  with  the  patella 
and  tibia. 

Leg. — This  part  contains  three 
bones, — the  tibia,  the  fibula,  and 
the  patella.  The  i^ihia  is  a  long 
bone  with  a  somewhat  triangular 
shaft  larger  at  the  upper  than  at 
the  lower  end.  It  articulates  above 
Avith  the  femur  and  fibula,  and  be- 
low with  the  bones  of  the  hock,  i.e. 
the  tarsal  bones.  Like  the  femur, 
this  bone  offers  for  study  a  distinct 
shaft,  upper  and  lower  extremities. 

The  shaft  of  the  tibia  presents 
three  surfaces, — the  external,  in- 
ternal, and  posterior;  and  three 
borders, — the  anterior,  external, 
and  internal.  The  superior  ex- 
tremity shows  in  front  a  depression 
for  one  of  the  ligaments  Avhich 
attaches  the  patella  to  the  tibia, 
also  a  small  articular  surface  for 
the  fibula  on  the  outer  side,  and 
two  oval  depressions  with  a  marked 
projection  between  them  for  articulating  with  the  condyles  of  the 
femur.  These  are  smooth  and  covered  with  a  thick  pad  of  fibro- 
cartilage.     The  inferior  extremity  presents  an  external  and  an 


Fig.  12. — Posterior  Limb  of 
THE  Horse. 

C,  Pelvic  bone;  F,  femur;  F, 

patella;   J,  tibia;  X,  fibula;  T, 

tarsals;      M,     metatarsals;  S, 
sesamoids;  P,  phalanges. 


16  VETERINARY  STUDIES 

internal  tuberosity.  Its  articular  surface  consists  of  two  shallow 
cavities  and  a  median  ridge,  all  three  of  which  extend  diagonally 
forward  and  backward. 

This  bone  articulates  with  four  others ;  viz.  femur,  fibula,  and 
one  of  the  tarsal  bones,  the  astragalus. 

The  fibula  is  a  small  rudimentary  bone  which  articulates  with 
the  external  portion  of  the  head  of  the  tibia,  and  is  situated  on 
the  external  side  of  that  bone. 

The  patella  is  small,  short,  and  located  in  front  of  the  lower 
extremity  of  the  femur,  and  attached  to  the  tibia  below  by  three 
strong  ligaments.  It  is  often  displaced  outward  Avhen  the  limb 
is  in  the  condition  popularly  known  as  "stifled."  This  bone 
offers  for  study  three  faces:  superior,  to  which  muscles  are 
attached;  the  anterior,  which  is  convex  and  somewhat  irregu- 
lar; and  the  posterior,  which  is  so  shaped  as  to  fit  nicely  into 
the  femoral  groove  already  mentioned. 

Foot. — In  its  anatomy,  the  foot  bears  a  very  close  resemblance 
to  the  corresponding  portion  of  the  anterior  limb,  and  is  divided 
for  study  into  the  tarsus,  metatarsus,  and  digit. 

The  tarsus  is  composed  of  six  or  seven  small  bones,  arranged 
in  two  rows,  forming  a  very  complicated  articulation  at  the 
hock.  The  upper  row  contains  the  astragalus  and  os  calcis.  The 
lower  row  usually  consists  of  four  small  bones.  Two  of  these 
are  especially  interesting  because  they  are  the  common  seat  of 
bone  spavin,  a  serious  cause  of  lameness  and  unsoundness. 

The  astragalus  is  interesting  because  it  furnishes  the  articu- 
lar surfaces  for  the  lower  end  of  the  tibia.  Note  the  peculiar, 
diagonal,  pulley-like  groove  with  which  the  astragalus  articu- 
lates with  the  tibia  and  its  important  bearing  in  the  action  of  the 
hock  and  cannon. 

The  OS  calcis  is  somewhat  elongated  and  lies  behind  the 
astragalus.  It  corresponds  to  the  prominent  portion  of  the 
human  heel  and  is  the  seat  of  the  "capped  hock."  The  bones 
of  this  region  correspond  to  the  human  tarsal  bones  making  up 
the  ankle. 

The  metatarsals  closely  resemble  the  metacarpals  of  the  front 
leg  and  consist  of  three  bones,  a  large  one  in  the  center  and 
one  small  rudimentary  bone  on  each  side,  i.e.  on  the  inside  and 
outside  of  the  middle  bone.  The  large  metatarsal  furnishes  the 
supporting  axis  for  this  region  as  in  the  anterior  limb.  The 
shaft  is  fairly  smooth  and  has  a  small  articular  surface  on  each 


POSTERIOR  LIMB  17 

side  for  the  rudimentary  metatarsal.  It  is  supposed  that  the 
small  metacarpal  and  metatarsal  bones  are  merely  survivals  in 
the  process  of  evolution,  and  that  in  the  primitive  animals  from 
which  the  modern  horse  is  descended  these  bones  were  larger 
than  they  are  now,  having  the  same  length  and  the  same  func- 
tional importance  as  the  principal  metacarpal  and  metatarsal 
bones.  The  original  ancestor  of  the  horse  is  supposed  to  have 
had  five  metacarpals  and  five  metatarsals  with  corresponding 
digits  or  toes,  and  to  have  walked  on  five  toes  instead  of  one. 

The  horse  has  three  phalanges  and  the  cow  six.  These  bones 
are  closely  similar  to  the  phalanges  of  the  front  pastern.  They 
are  commonly  known  as  the  first,  second  and  third  phalanges, 
or  OS  sulfraginis,  os  corona,  and  os  pedis. 

The  sesamoids  and  navicular  bones  are  very  similar  to  the 
corresponding  bones  of  the  front  limb  already  described.  Ani- 
mal-husbandry students  should  find  the  application  of  preced- 
ing lessons  helpful  by  giving  a  clear  view  of  the  anatomical 
basis  of  conformation,  type  and  action. 

Practical  application. — Note  how  the  external  angle  of  the 
iliutn  lixes  the  "rouglmess"  or  "smoothness"  of  the  hips;  how 
the  length  and  slope  of  the  femur  fixes  the  length  and  slope  of 
the  thigh,  and  controls  the  action  of  the  limb,  for  example  the 
cow  and  hog  have  comparatively  horizontal  femurs  and  are 
awkward  travelers.  Note  the  tihia  in  its  relation  to  length  and 
slope  of  the  leg  or  gaskin,  or  lower  thigh,  as  this  region  is  vari- 
ously named,  and  how  this  affects  the  stride  of  the  roadster. 

The  tarsal  bones  make  the  framework  and  determine  largely 
the  conformation  and  strength  of  the  hock. 

Whether  the  point  of  the  hock  is  prominent  or  otherwise  de- 
pends on  the  OS  calcis,  one  of  the  tarsal  bones.  Good  hock  action 
depends  to  an  important  extent  upon  the  peculiar  obli({ue  articu- 
lar surfaces  of  the  astragalus  and  tibia.  The  principal  meta- 
tarsal determines  the  length  of  the  cannon,  and  this  in  turn 
affects  the  stride  of  the  roadster  and  the  power  of  the  draft 
horse. 

Length  and  slope  of  the  pastern  depends  on  length  and  slope 
and  articulations  of  the  first  and  second  phalanges  and  these 
give  elastic  spring  or  jar  and  cause  the  horse  to  go  clear  or 
interfere  at  the  ankle. 

Disorders  of  the  posterior  limb  are  even  more  numerous  than 
those  of  the  fore  limb.     The  three  pelvic  bones  are  all  subject 


18  VETERINARY  STUDIES 

to  fracture  and  in  the  female  this  may  interfere  with  the  birth 
of  her  young. 

The  external  angle  of  the  ilium  is  often  fractured,  causing  the 
deformity  known  as  "hipped"  or  "hip  shot."  The  shaft  of  the 
femur  is  occasionally  fractured  as  in  throwing  for  surgical 
operation — usually  a  hopeless  fracture,  except  in  very  young 
animals.  The  patella  of  the  horse  is  quite  subject  to  dislocation 
over  the  external  condyle  of  the  femur  causing  the  condition 
known  as  "stifled,"  the  horse  being  unable  to  bring  the  hind 
leg  forward.  The  shaft  of  the  tibia  is  a  common  seat  of  frac- 
ture, usually  from  kick  while  weight  is  on  the  injured  limb. 
The  tarsal  bones  at  the  lower,  inner,  front  part  of  the  hock  are 
often  affected  with  bone  spavin,  due  to  injury  and  heredity  and 
usually  characterized  by  local  inflammation,  an  abnormal  growth 
of  bone  (exostosis)  and  a  typical,  chronic  lameness.  The  meta- 
tarsals, phalanges,  and  navicular  bones  are  subject  to  about  the 
same  disorders  as  the  corresponding  parts  of  the  front  limb. 


LECTURE  V 


THE  FOOT 

The  foot,  technically,  includes  all  structures  at  and  below 
the  knee  in  front  and  the  hock  behind.  This  lecture  only  deals 
with  that  portion  of  the  foot  below  the  ankle. 

Bones. — First  phalanx ;  two  sesamoid  bones ;  second  phalanx ; 
navicular  bone ;  and  third  phal- 
anx.    For  first  and  second  phal- 
anges, sesamoids,  and  navicular, 
see  Lecture  III. 

The  third  phalanx  is  an  irregu- 
lar bone  of  loose  spongy  texture. 
The  body  is  shaped  somewhat 
like  the  hoof  and  shows  at  the 
top  in  front  a  prominence  called 
the  pyramidal  process,  and  on 
each  side  a  projection  called  the 
wing,  under  which  may  be  seen  a 
groove,  through  which  groove  an 
artery  passes  on  its  way  to  form 
part  of  an  arch  within  the  sub- 
stance of  the  bone.  From  this 
arch  are  given  off  the  branches 
which  distribute  nourishment  to 
the  vascular  parts.  Above  the 
wings,  inside  the  hoof,  are  cavi- 
ties into  which  the  lateral  car- 
tilages fit.  They  are  of  firm 
cartilage  and  may  be  felt  above 
the  crown  of  the  hoof  on  each 
side.     They   are   attached   below 

to  the  wings  of  the  third  phalanx  and  plantar  cushion.  To  the 
front  and  sides  of  the  third  phalanx  are  attached  the  sensitive 
laminae.  The  inferior  surface  is  concaved  to  receive  the  sensi- 
tive sole,  or  velvety  tissue. 

19 


Fig.  13. — Boxes  of  the  Horse's 
Foot. 

1,  Metacarpal;  2,  sesamoids; 
3,  first  phalanx;  4,  second  pha- 
lanx; 5,  navicular  bone;  6,  third 
phalanx  (os  pedis)  ;  7,  basilar 
I)rocess;  8,  8,  wings;  9,  pyramidal 
process. 


20 


VETERINARY  STUDIES 


The  navicular  hone  is  also  a  sesamoid  bone;  i.e.,  it  is  formed 
in  tendon.  It  is  a  short  bone  in  structure,  but  rather  long  and 
slender  in  shape,  and  placed  crosswise  just  back  of  the  articu- 
lation between  the  second  and  third  phalanges.  Its  inferior 
surface  is  smooth  except  for  a  slight  ridge  in  the  center.  The 
tendon  of  the  deep  flexor  muscle  passes  over  this  surface  on  its 
way  to  its  insertion  on  the  bottom  of  the  third  phalanx.  The 
ends  of  the  navicular  bone  unite  on  each  side  with  the  wings  of 
the  third  phalanx  by  tough  fibrous  tissue. 


Fig.  14. — The  Hoof. 

The  Wall.     A,  Toe;  B,  quarter;  C,  heel. 

Ground  Surface,  a-a,  toe;  a-b,  quarter;  b-d,  heel;  c,  bar;  /,  /,  /,  sole; 
g,  white  line;   h,  frog;   /,  cleft  of  the  frog. 

Horny  hoof. — This  is  to  be  regarded  as  an  appendage  of  the 
skin.  It  covers  all  of  the  third  phalanx  and  part  of  the  second. 
It  is  divided  for  study  into  wall,  sole,  and  frog. 

The  wall  is  that  part  which  may  be  seen  when  looking  at  the 
hoof  in  front  and  at  the  sides  when  the  foot  is  on  the  ground. 
It  is  composed  of  horny,  tubular  fibers,  which  grow  from  the 
coronary  band.  Between  these  tubular  fibers  is  a  material  which 
holds  them  together.  The  wall  is  divided  into  toe,  ciuarters,  and 
heels.  At  the  top  is  a  groove  into  which  the  coronary  band  fits, 
the  crown  of  the  hoof.  The  wall  unites  below  with  the  sole. 
The  smooth  shining  layer  which  should  cover  the  surface 
of  the  wall  is  periople.  The  duty  of  this  layer  is  to  prevent 
undue  evaporation  from  the  hoof.  Beneath  the  periople  is  the 
horny  wall  which  gives  shape  to  the  foot  and  protects  the  soft 
parts  w'ithin.  Inside  this  hard  layer  come  the  laminae;  these 
are  thin  leaves  of  horny  material  which  dovetail  in  with  the 
sensitive  laminae. 


THE  FOOT 


21 


The  sole  is  composed  of  horny  material  resembling  that  of  the 
wall.  It  is  concave  below,  convex  above.  Its  outer  border 
unites  with  the  wall  at  the  "white  line."  Its  upper  surface  is 
covered  by  the  vascular  velvety  tissue. 

The  frog  is  a  V-shaped  elastic  pad  with  a  depression,  called 
by  horsemen  "the  cleft,"  in  its  ground  surface.  It  is  located 
between  the  bars  on  each  side,  and  below  the  plantar  cushion. 
Its  function  is  to  act  as  a  pad  and  to  lessen  jar  when  traveling. 

Matrix.— The  matrix  (horn-generating  membrane)  fits  inside 
of  the  horny  part  of  the  hoof  and  covers  like  a  stocking  the 
other  parts  within  the  hoof.  It  is 
from  this  that  all  the  horny  parts 
grow.  It  is  composed  of  three 
parts:  (1)  coronary  band;  (2) 
sensitive  lamina;  (3)  velvety  tis- 
sue. 

The  coronary  hand  is  the  elastic 
ring  that  may  be  felt  at  the  crown 
of  the  hoof.  It  is  studded  with 
little  papilla'.  From  these  grow 
downward  the  tubular  fibers  which 
make  up  the  hard  layer  of  the  wall. 

The  sensitive  lamina;  are  500  to 
600  layers  of  vascular  tissue  into 
which  fit  and  from  which  grow 
the  horny  lamina?  of  the  w'all.  An 
inflammation  here  is  called  lamin- 
itis  or  founder. 

The  velvctij  tissue  covers  the  upper  surface  of  the  hard  sole. 
Like  the  coronary  band  and  sensitive  lamina?,  it  is  sensitive  and 
richly  supplied  witli  blood.  The  under  surface  is  thickly 
studded  with  papilke,  similar  to  those  of  the  coronary  band,  and 
from  these  in  a  similar  way  grow  the  shorter  tubular  fibers 
which  make  up  the  hard  sole  and  frog.  Tiic  student  can  easily 
understand  why  injury  to  the  coronary  band,  e.g.  a  wire  cut 
which  results  in  a  healing  by  scar  tissue,  leaves  a  split  which 
lengthens  downward  in  the  hoof ;  why  founder  is  so  ])ainful ;  and 
why  deep  injuries  to  the  sole  are  so  apt  to  be  serious. 

Plantar  cushion. — This  is  a  wedge-shaped  mass  of  elastic  tis- 
sue located  between  the  lateral  cartilages  on  each  side,  below 
the  sole  of  the  third  phalanx  and  above  the  horny  sole  of  the 


Fig.  15. — The  Hoop  Matrix. 

1,  Periople  ring;  2,  coronary- 
baud;  3,  sensitive  lamina;  4, 
heel.  Velvety  tissue  ou  the 
sole  not  shown. 


22  VETERINARY  STUDIES 

hoof.     It  assists  the  horny  frog  in  lessening  jar  in  travel  and 
protects  the  insertion  of  the  deep  flexor  tendon. 

"Back  tendons." — This  is  a  term  used  by  horsemen  to  include 
the  tendons  of  the  superficial  and  deep  flexor  muscles  of  the  foot 
and  the  suspensory  ligament. 

The  superficial  flexor  muscle,  of  the  front  foot,  has  its  origin 
on  the  lower  end  of  the  humerus  and  its  insertion  by  tendon  on 
the  sides  of  the  second  phalanx.  Its  function  is  to  flex  the  foot 
at  the  first  interphalangeal  articulation. 

The  deep  flexor  muscle,  of  the  front  foot,  has  its  origin  in 
common  with  the  superficial  flexor  on  the  lower  end  of  the 
humerus,  and  its  insertion  by  a  tendon  which  spreads  out  on 
the  sole  of  the  third  phalanx.  Its  duty  is  to  flex  the  second  and 
to  assist  in  flexing  the  first  interphalangeal  articulation. 

The  suspensory  ligament  is  broad  and  very  strong.  It  at- 
taches by  its  upper  end  to  the  carpal  bones  and  to  the  large 
metacarpal.  Its  lower  end  divides  into  two  branches  which  pass 
forward  on  each  side  and  attach  to  the  front  tendon.  Its  duty 
is  to  support  the  metacarpo-phalangeal  articulation    (fetlock). 

Practical  application. — The  shape  and  peculiar  characteristics 
of  each  hoof  correspond  by  correlation  with  the  remainder  of 
the  limb,  except  as  the  hoof  has  been  varied  by  artificial  means. 
So  in  judging  the  hoof  it  is  also  necessary  to  consider  the  char- 
acteristics of  the  entire  limb. 

The  front  limb  may  be  said  to  be  normal  in  position  and  direc- 
tion when  it  appears  on  front  view  that  a  vertical  line  from  the 
front  of  the  scapulo-humeral  articulation  passes  down  the  center 
of  the  limb  and  to  the  ground  at  the  center  of  the  toe. 

On  viewing  such  a  limb  from  the  side  it  should  be  evident 
that  a  vertical  line  downward  from  the  bony  prominence  at  the 
middle  of  the  scapula  would  divide  the  external  surface  of  the 
limb  into  two  equal  portions  and  reach  the  ground  immediately 
back  of  the  heels. 

Viewing  the  hoof  and  pastern  alone  it  should  be  seen  that  the 
hoof  is  in  direct  line  with  the  pastern  and  metacarpal  or  meta- 
tarsal bones,  and  that  a  line  extending  from  the  center  of  the 
cannon  through  the  center  of  the  pastern  would  pass  through 
the  center  of  the  toe. 

The  hind  limb  when  viewed  from  behind  should  show  that  a 
vertical  line  downward  from  the  prominence  at  the  posterior 
portion  of  the  pelvis  on  each  side  (tuberosity  of  the  ischiiun) 


THE  FOOT  23 

would  divide  the  entire  limb  into  two  eqnal  portions  and  reach 
the  ground  back  of  the  center  of  the  horny  frog-. 

For  the  front  hoof  the  wall  at  the  toe  and  the  anterior  sur- 
face of  the  pastern  should  make  an  angle  of  not  less  than  45  nor 
more  than  50  degrees  with  the  level  ground  surface,  the  wall  at 
the  toe  and  the  anterior  surface  of  the  pastern  having  the  same 

slant. 

For  a  normal  hind  hoof  the  angle  should  be  from  50  to  55 
degrees,  and  the  anterior  faces  of  the  hoof  and  pastern  should 
still  have  the  same  slant. 

A  normal  hoof  has  a  good  quality  of  horn,  and  moderately 
wide  heels.  The  hind  hoof  is  narrower  and  more  pointed  at  the 
toe  than  the  front  hoof.  The  wall  from  coronary  band  to  ground 
surface  should  be  straight  and  smooth.  The  heels  should  be 
rounded,  well  developed,  and  of  the  same  height  at  the  top  of 
the  coronary  band.  The  sole  should  be  distinctly  concave  and 
show  no  marked  separation  from  the  wall.  The  frog  should  be 
large  and  elastic,  the  two  portions  of  the  same  size,  with  a 
shallow  groove  along  the  center.  The  bars  should  be  straight, 
extending  forward  and  inward.  The  lateral  cartilages,  felt 
above  the  coronary  band  on  each  side,  should  be  elastic.  The 
sole  in  the  angles  between  the  bar  and  the  wall  at  the  heel 
should  not  show  red  stain.  There  should  be  no  separation  of 
the  horny  fibers  as  in  toe  or  quarter  cracks.  The  wall  should  be 
reasonably  thick.  This  can  be  usually  determined  by  tapping 
the  wall  with  a  hammer,  noticing  its  rigidity. 

Disorders  of  the  foot  are  mentioned  in  connection  with  the 
anatomy  of  the  anterior  and  posterior  limbs. 


LECTURE    VI 
ARTICULATIONS  OR  JOINTS 

Articulations  are  divided  into  several  groups  for  the  pur- 
pose of  stud}^  These  groups  are:  immovable,  slightly  movable, 
and  freely  movable. 

Examples:  Immovable,  between  the  skull  bones;  slightly  mov- 
able, between  vertebrae ;  freely  movable,  between  scapula  and 
humerus. 

Freely  movable  articulations. — The  freely  movable  articula- 
tions are  subdivided  according  to  shapes  of  the  articular  sur- 
faces and  varieties  of  movement  that  can  be  produced.  These 
subdivisions  are:  ball-and-socket,  hinge,  pivot,  imperfect  hinge, 
and  gliding. 

The  haU-and-socket  articulation,  of  which  we  find  examples 
at  the  shoulder  and  hip,  is  made  by  a  rounded  head  of  one  bone 
fitted  into  a  rounded  cavity  of  some  other  bone ;  for  instance,  at 
the  shoulder  we  have  a  rounded  head  of  the  humerus  fitted  into 
the  glenoid  cavity  of  the  scapula.  At  the  hip  a  rounded  head  on 
the  superior  extremity  of  the  femur  fits  perfectly  into  the  coty- 
loid cavity  of  the  pelvic  bone.  It  will  be  readily  seen  that  the 
ball-and-socket  joint  permits  the  greatest  variety  of  movements. 

The  hinge  joint  is  made  by  two  articular  surfaces  of  such 
shape  and  so  fitted  together  that  no  lateral  or  rotary  motion  is 
possible.  Only  two  movements  are  allowed  at  joints  of  this 
kind :  flexion  and  extension.  The  articulation  between  the 
humerus  above  and  the  ulna  and  radius  below  offers  a  good 
example  of  this  kind. 

Pivot  joint  is  one  where  portions  of  two  bones  are  in  contact 
in  such  a  way  as  to  permit  of  rotary  motion ;  for  example,  be- 
tween the  atlas  and  axis,  the  rotation  being  around  the  odon- 
toid or  toothlike  processes  of  the  axis.  Articulations  of  this 
kind  permit  of  rotation  only. 

The  imperfect  hinge  joint  is  one  which  permits  of  two  prin- 
cipal motions — flexion  and  extension,  and  to  a  limited  extent 
some  other  motion,  as  for  instance  rotary  or  lateral  movement. 

24 


ARTICULATIONS  OR  JOINTS  25 

We  may  find  a  type  of  this  articulation  between  the  temporal 
and  inferior  maxillary  bones,  or  between  the  femnr  and  tibia. 
Articulations  of  this  kind  are  formed  by  oval  heads  fitting  in 
oval  sockets. 

Gliding  joints  permit  only  simple  gliding  movement  between 
the  articular  surfaces.  The  articular  surfaces  in  joints  of  this 
kind  are  more  or  less  nearly  flat. 

Immovable  articulations. — At  immovable  articulations  the 
bones  are  united  by  cartilage  and  practically  continuous.  The 
only  movement  permitted  is  by  cartilage  elasticity,  as  between 
the  cranial  and  the  pelvic  bones. 

Slightly  movable  articulations. — At  slightlij  movable  articu- 
lations, bones  are  unitctl  by  a  cartilage  which  is  elastic  enough 
to  permit  of  slight  movement,  e.g.  the  common  intervertebral 
articulations. 

At  freely  movable  artiouUUions  the  articulating  bony  surfaces 
are  each  covered  by  a  thin  layer  of  smooth,  glistening,  and  elas- 
tic articular  cartilage.  This  cartilage  gives  a  smooth  gliding 
surface.  It  also  lessens  jar  by  its  elasticity  and  protects  the 
bony  surface  beneath. 

Structures  at  joints. — These  structures  are  bones,  cartilage, 
ligaments,  tendons,  muscles,  synovial  membrane,  and  synovial 
fluid.    Any  or  all  of  these  may  be  involved  in  injury  and  disease. 

Ligaments  are  either  bands  or  sheets  of  white  or  yellow  con- 
nective tissue.  The  white  ligaments  are  very  strong  and  in- 
elastic. Their  sole  function  is  to  hold  bones  together  at  articu- 
lations. The  yellow  ligaments  are  composed  of  yellow^  elastic 
connective  tissue,  and  are  especially  useful  as  assistants  to 
muscles,  particularly  in  supporting  parts  of  the  body,  like  the 
head  of  the  horse,  which  constantly  tend  to  fall. 

Synovial  memhrancs  are  sometimes  called  capsules.  These 
are  serous  membranes,  quite  thin,  but  composed  of  two  layers, 
deep  and  superficial.  Tliis  membrane  affords  at  each  joint  a 
closed  sack  and  is  for  the  purpose  of  secreting  synovia.  The 
synovial  membrane  does  not  cover  the  surface  of  the  articular 
cartilage,  as  is  frequently  supposed,  but  incloses  the  articula- 
tion like  a  sack,  being  attached  at  one  side  near  the  edge  of 
the  articular  surface  of  one  bone,  and  at  tlie  otlier  side  near  the 
articular  edge  of  the  otlier  bone.  The  synovial  membrane  is 
usually  attached  also  to  the  inner  surface  of  the  capsular  or 
other  ligaments  of  the  joint.     Disease  and  injury  of  a  synovial 


26  VETERINARY  STUDIES 

membrane  are  always  serious,  as  for  example,  "open  joint,"  and 
this  is  true  of  all  serous  membranes  in  general. 

Synovia  is  a  viscid  fluid,  slightly  yellow  or  nearly  colorless. 
It  has  an  oily  feeling,  but  is  not  an  oil  chemically.  This  fluid 
is  quite  rich  in  albumen,  which  gives  it  the  viscid  property, 
and  adapts  it  so  well  for  lubricating  articular  surfaces.  Muscles 
and  tendons  are  discussed  in  Lecture  VII. 

Kinds  of  motion. — These  are :  flexion,  or  bending,  in  which  the 
two  articulating  bones  are  brought  nearer  each  other ;  extension, 
the  reverse  of  flexion,  by  which  bones  are  straightened  on  each 
other;  adduction,  bringing  the  lower  extremity  of  the  moving 
bone  toward  the  median  line;  abduction,  in  which  the  lower 
end  of  the  moving  bone  is  carried  from  the  median  line ;  circum- 
duction, in  which  the  articulation  forms  the  apex  of  a  cone  cir- 
cumscribed by  the  moving  bone;  rotation,  in  which  one  bone 
rotates  as  a  pivot  on  another. 

Joints  are  named  according  to  the  bones  involved.  In  the 
limbs  the  upper  bone  is  named  first.  In  the  vertebrse,  the  an- 
terior bone  is  named  first. 

Describing  Articulations,  Examples  ^ 

Scapulo-humeral  articulation. — This  is  a  ball-and-socket  joint, 
the  rounded  head  of  the  humerus  fitting  the  glenoid  cavity  of 
tlie  scapula. 

Ligaments  at  this  joint  are:  (a)  glenoid,  a  cartilaginous  rim 
around  the  cavity  which  deepens  the  cavity;  (&)  capsular,  a 
sort  of  capsule  fitting  around  the  joint  like  a  bag;  (c)  two 
bundles  of  ligament  fibers  in  front  of  the  joint  connecting  the 
extremities  of  the  scapula  and  humerus. 

Movements. — All  the  motions,  except  true  gliding,  are  pos- 
sible at  this  articulation.  The  synovial  membrane  is  quite  loose 
and  affords  a  lining  for  the  capsular  ligament. 

First  interphalangeal  articulation. — This  is  an  imperfect 
hinge  joint.  The  articular  surface  of  the  inferior  extremity  of 
the  first  phalanx  is  characterized  by  two  condyles  and  a  median 
groove  which  fit  with  two  shallow  cavities  and  a  median  ridge 
on  the  superior  extremity  of  the  second  phalanx. 

Ligaments. — The   articular   extremities   which   make  up   this 

articulation  are  supported  by  the  following  ligaments  and  ten- 

^  All  freely  movable  articulations  are  described  in  this  general  way 
in  anatomy. 


ARTICULATIONS  OR  JOINTS  27 

dons:  in  front  by  the  tendon  of  the  anterior  extensor  mnsele; 
on  the  sides  by  two  lateral  ligaments,  one  on  each  side ;  behind 
by  the  posterior  ligament  and  the  tendons  of  the  shallow  and 
deep  tlexor  mnscles  which  pass  over  the  posterior  of  the  joint. 
The  posterior  ligament  is  really  a  thick  strong  pad  of  iibro- 
cartilage. 

Movements. — Flexion  and  extension,  together  with  a  limited 
lateral  movement. 

Practical  application  and  disorders. — Among  the  more  com- 
mon disorders  of  articulations  are  sprains,  dislocations,  syno- 
vitis, arthritis,  open  joint,  and  anchylosis. 

A  sprain  is  an  injury  due  to  a  strain  of  articular  structures, 
especially  ligaments,  overstretching  or  actually  rupturing  the 
fibers.  Sprains  are  characterized  by  the  usual  symptoms  of 
intiammation,  pain,  heat,  swelling,  etc.;  disinclination  to  flex 
the  joint  or  bear  weight  upon  it,  most  common  at  ankle,  hock 
and  stifle.  Treat  by  complete  rest,  fixation  if  necessary,  cold 
water  or  ice  several  days,  then  massage  and  light  use  soon  as 
appears  advisable. 

Dislocation  may  be  partial  or  complete  and  implies  that  a  bone 
Is  out  of  its  proper  place  at  an  articulation.  This  is  usually 
the  result  of  severe  injury,  and  it  is  frequently  associated  with 
sprain  of  ligaments  or  other  structures.  It  is  indicated  by 
change  in  length  or  shape  of  the  limb,  by  either  more  or  less 
mobility,  and  frequently  by  pain,  heat,  and  swelling.  Reduce 
the  dislocation  by  pulling  and  pushing  the  bone  back  into  place 
and  treat  as  for  sprain. 

SynovUis  is  an  inflammation  of  the  synovial  membrane,  usually 
the  result  of  injury  or  infection.  Very  mild  form  is  seen  in 
bog  spavins,  wind  puffs,  etc.  Severe  and  acute  cases  occur, 
for  example,  in  connection  with  open  joint  where  we  have  ex- 
treme pain  and  lameness.  The  most  conspicuous  symptom  is 
bulging  of  the  synovial  capsule  with  or  without  lameness. 

Arthritis  implies  a  general  inflammation  of  local  articular 
structures,  including  synovial  membrane  (synovitis),  articular 
cartilage,  bone,  ligaments,  etc.  Arthritis  is  characterized  espe- 
cially by  lameness,  local  tenderness,  pain  and  swelling.  Ar- 
ticular rheumatism  is  a  good  example.  Bone  spavins  and  articu- 
lar ring  bones  illustrate  the  results  of  an  arthritis  in  which 
articular  cartilages  and  adjacent  bones  are  seriously  involved. 
Treatment  of  severe  arthritis  must  be  left  to  the  veterinarian. 


28  VETERINARY  STUDIES! 

Opefi  Joint  implies  that  the  capsular  ligament  and  synovial 
membrane  have  been  punctured,  as  by  a  nail  in  the  foot,  or  by 
barb-wire  cut  at  the  hock.  This  is  usually  followed  by  infection 
and  is  characterized  by  extreme  pain,  swelling,  tenderness,  lame- 
ness and  especially  by  the  great  pain  and  escape  of  synovia. 
This  is  always  a  serious  disorder  and  must  be  left  to  a  competent 
veterinarian. 

Anchylosis  implies  union  of  two  or  more  bones  at  a  normally 
movable  articulation.  It  is  the  result  of  inflammation  of  perios- 
teum, articular  cartilage  and  bone.  The  cartilage  is  destroyed 
and  the  bones  become  united,  resulting  in  a  "stift"- joint"  often 
seen  in  ringbone  and  bone  spavin. 


LECTURE  VII 
MUSCULAR  SYSTEM 

The  peculiar  property  of  muscle  tissue  is  the  power  of  self- 
contraction  and  self-movement.  The  muscles  of  the  animal  body 
are  of  tliree  kinds,  voluntary,  involuntary,  and  heart  muscle. 

Involuntary  muscles  act  independently  of  the  will,  and  are 
under  the  control  of  the  sympathetic  and  cerebrospinal  nervous 
systems. 

Voluntary  muscles  are  under  the  control  of  the  will  through 
the  cerebrospinal  nervous  system. 

Heart  muscle  is  not  under  control  of  the  will  but  is  similar 
to  voluntary  muscle  in  structure. 

Voluntary  muscles. — What  is  popularly  termed  "lean  meat" 
is  composed  of  voluntary  muscles.  These  are  classified  into 
simple,  digastric,  biceps,  triceps,  penniform,  bipenniform.  The 
bcllij  is  the  active  working  part  (lean  meat).  The  tendon  is  a 
strong  cord  or  band  of  white  connective  tissue.  This  merely 
serves  to  give  connection  with  a  distant  object,  usually  a  bone. 
Tendons  are  strong,  but  have  no  power  of  contraction.  The 
strength  of  a  muscle  depends  upon  the  thickness  of  the  belly. 
The  extent  of  its  movement  depends  upon  the  length  of  the 
belly. 

The  two  ends  of  a  muscle  are  defined  as  origin  and  insertion. 
The  origin  is  the  less  movable  end;  insertion  the  more  movable 
end.  It  may  happen  at  one  time  that  one  end  is  the  insertion, 
at  another  time  the  origin. 

A  simple  muscle  is  characterized  by  a  single  belly  with  not 
more  than  one  tendon  at  either  end;  a  digastric  muscle  has  two 
bellies  connected  by  a  tendon;  a  biceps  muscle  has  two  tendons 
at  one  end ;  a  triceps  muscle  has  three  tendons  at  one  end. 

They  are  also  classified  according  to  function  into  flexors, 
extensors,  abductors,  adductors,  and  rotatore. 

Muscles  are  paired  in  a  double  sense.  The  rule  is  that  for 
any  given  muscle  there  is  a  corresponding  muscle  on  the  other 

29 


30 


VETERINARY  STUDIES 


side  of  the  body,  and  also  one  or  more  opposing  muscles  on  its 
own  side. 

The  belly  of  a  muscle  has  a  rich  blood  supply ;  the  tendon  has 
very  little. 

A  muscle  produces  motion  by  pulling  upon  some  bone  which 
acts  as  a  lever  with  the  fulcrum  at  a  joint. 

The  muscle  fibers  may  attach  directly  to  the  bone,  or  indirectly 
through  tendon  fibers.  The  connection  between  the  muscle 
fiber  and  the  tendon  fiber  is  by  insertion  of  the  conical  point  of 


Fig.  16. — ^^"oluntary  Muscle.     {M.  H.  E.) 

1.  Action  of  Muscle  in  Producing  Motion.  Muscle  does  its  work  by 
shortening  its  belly.  A,  A,  bones;  B,  B,  tendons;  C,  belly  of  muscle;  E, 
articulation    (joint). 

2.  Muscle  in  Cross  Section.  Showing  "bundle  of  bundles"  arrangement 
of  the  fibers.     Dots  represent  single  fibers. 

3.  Diagram  of  Simj^le  Muscle.    B,  B,  tendons;  C,  belly  (lean  meat). 


the  muscle  fiber  into  a  conical  cavity  at  the  end  of  the  tendon 
fiber. 

Structure. — The  voluntary  muscle  consists  of  bundles  of 
bundled  fibers ;  each  individual  fiber  has  its  own  delicate  sheath. 
A  number  of  fibers  are  inclosed  within  a  common  connective 
tissue  sheath  and  constitute  a  minute  bundle.  A  number  of 
these  bundles  are  in  turn  wrapped  within  a  connective  tissue 
sheath,  forming  a  larger  bundle.  These  larger  bundles  may  in 
turn  be  wrapped  by  means  of  another  connective  tissue  sheath 
into  a  still  larger  bundle. 

The  voluntary  muscle  fiber  is  long,  threadlike,  marked  by 
cross  stripes  which  are  very  close  together,  and  may  end  in 
tendon  fiber.  These  muscle  fibers  are  about  1/1500  of  an  inch 
wide,  but  may  be  very  long — one  inch  or  less. 


MUSCULAR  SYSTEM 


31 


Involuntary  muscles. — Involuntary  muscle  fibers  have  the 
peculiar  property  of  being  able  to  act  independently  of  the  will 
in  contraction  and  relaxation.  They  are  controlled  in  this  action 
by  two  kinds  of  motor  nerve  fibers  from  the  sympathetic  and 
cerebrospinal  nervous  systems.  One  kind  stimulates,  causing 
contraction ;  the  other  kind  inhibits,  causes  relaxation  of  the  in- 
voluntary muscle  fibers.  These  are  merely  long,  spindle-shaped 
cells,  which  do  not  end  in  tendon  fibere.  They  may  be  arranged 
in  the  form  of  small  bun- 
dles, and  are  usually  in  the 
form  of  thin  sheets.  Invol- 
untary muscle  tissue  is 
lighter  in  color  than  volun- 
tarv,  and  usually  incloses 
hollow  organs  forming  one 
of  the  coats  or  layers.  The 
middle  coat  of  the  stomach 
and  intestines  is  composed 
of  involuntary  muscle  fibers. 

Function.  —  It  is  their 
function  to  carry  on  work 
which  could  not  be  intrusted 
to  conscious  control  and 
with  which  the  brain  could 
not  well  be  burdened. 

Peristaltic  action  of  the 
stomach  and  intestines  is 
produced  by  the  rhythmic 
action  of  these  muscle  fibers.  The  lieart  muscle  fibers  differ 
from  botli  the  typical  voluntary  and  the  typical  involuntary 
fibers.     They  arc  striped,  but  operate  independently  of  the  will. 

Source  of  heat  and  power. — Muscular  power  comes  from 
oxidation  of  food  material  in  the  various  tissues  of  the  body, 
particularly  in  the  muscles  and  larger  glands.  During  the 
process  of  oxidation,  carbonic  gas  and  other  materials  are  de- 
veloped. Power  is  increased  by  proper  nourishment,  and  is 
decreased  by  lack  of  nourishment.  IMuscles  lose  in  strength  by 
overwork  because  they  are  consumed  more  rapidly  tlian  rebuilt. 

Description  of  voluntary  muscle. — Tlie  massetcr  muscle  is 
located  on  the  outer  part  of  the  cheek.  Form,  flat,  broad,  thick, 
four-sided.      Origin,   on   the   temporal   and  superior   maxillary 


Muscle  Fibers. 


A,  Bundle  of  voluntary  fibers,  side 
view.  B,  C,  D,  Three  involuntary  fibers, 
spindle-shaped  cells  with  nuclei. 


32  VETERINARY  STUDIES 

bones.  Insertion,  on  the  outer  surface  of  the  inferior  maxillary. 
Action,  elevates  the  lower  jaw.  Nerve  supply,  from  a  branch 
of  the  fifth  cranial  nerve  (trifacial). 

Practical  application. — The  student  should  now  make  prac- 
tical observations  for  himself,  recording  as  in  previous  lectures. 
He  may  select  at  the  teacher's  discretion  several  short  thick 
muscles  and  several  long  slender  ones,  and  should  note  locations, 
attachments,  and  probable  functions,  and  should  make  a  state- 
ment concerning  the  probable  working  efficiency  of  muscles  of 
these  different  types.  This  refers  to  the  amount  of  load  to  be 
moved  and  long  or  short  distance  of  movement. 

Study  a  skeleton,  and  also  a  horse  in  motion,  and  note 
how  the  horse  pulls,  or  lifts  a  load.  What  occurs  at  the  articula- 
tions and  how  is  this  brought  about  ? 

Study  the  location  and  size  of  muscles  and  the  relations  of 
these  considerations  to  body  conformation. 

Note  how  the  voluntary  muscles  supplement  the  bony  frame- 
work in  giving  conformation  and  type  in  shape  of  neck,  smooth- 
ness of  shoulder,  width  of  back  and  loin,  type  of  quarter,  fore- 
arm, gaskin,  lower  thigh  or  ''twist." 

Short,  heavy  muscles  (bellies)  produce  powerful  but  short 
action ;  long,  slender  muscles  reverse  this  and  give  weak  power 
and  long  movement. 

Disorders  are  numerous.  Wounds  are  common  and  repair 
is  only  fairly  good — partly  by  connective  tissue  in  place  of 
the  normal  muscle.  Sprains  are  similar  in  nature,  symptoms, 
and  treatment  to  those  described  for  ligaments  in  the  preceding 
chapter. 

Atrophy  (sweeny),  e.g.,  of  the  shoulder  and  hip  muscle,  is  a 
common  disorder  of  muscle  tissue.  Treatment  must  remove 
the  cause,  often  a  severe  lameness  elsewhere,  and  improve  nutri- 
tion of  the  wasted  muscle  by  rich  blood  supply  to  it,  by  lini- 
ment, blister,  or  irritating  injections,  for  example.  Muscle 
tissue  is  subject  to  various  disorders  such  as  fatty  infiltration  of 
the  heart  muscle  in  old  and  excessively  fat  horses  and  dogs. 


LECTURE  VIII 

NERVOUS  SYSTEM 

Function. — The  peculiar  function  of  the  nervous  system  is 
to  control  the  various  organs  and  systems  of  the  body,  and 
compel  them  to  work  in  harmony.     The  peculiar  property  of 


Fig.  18. — Cerebrospinal  Nervous  System. 

1,  Brain;  2,  optic  nerve;  3,  superior  maxillary  nerve;  4,  inferior  niaxillary 
nerve;  5,  pneumogastrie  nerve;  6,  spinal  cord;  10,  radial  nerve;  11,  median 
nerve;  12,  pneumogastrie  nerve;  13,  portion  of  solar  plexus;  14,  solar 
plexus;  17,  sciatic  trunk;  19,  great  sciatic  nerve;  20,  posterior  tibial  nerve; 
21,  posterior  plantar  nerve;  22,  internal  radial  nerve;  23,  anterior  plantar 
nerve;  24,  digital  nerves. 

nerve  tissue  is  irritability.     The  nervous  system  is  composed  of 
nerve  centers,  nerves,  and  nerve  cells  or  neurons. 

A  nerve  center  is  composed  of  nerve  cells  or  neurons  with 
their  bi-anches:  (a)  (axons) — commonly  called  nerve  fibers — 
over    which    impulses    pass    from    the    cells,    and    (&)    shorter 

33 


34 


VETERINARY  STUDIES 


Dendh'tes 


Ce//   body 


Axon 


branches  (dendrites),  over  which  impulses  come  to  the  cell  body 
from  the  axon  of  some  other  cell  or  from  a  terminal  sense  organ, 
as  a  taste  bud  on  the  tongue  or  a  tactile  (sense  of  touch) 
corpuscle  in  the  skin,  connective  tissue,  and  blood  vessels.  The 
function  of  a  nerve  center  is  to  receive  and  dispose  of  impres- 
sions which  may  be  brought  to  it,  to  provide  connection  for  nerve 

fibers,  and  in  the  case  of  the 
forebrain  to  originate  conscious 
impulses. 

Some  nerve  fibers  or  axons  are 
composed  of  a  central  filament, 
the  axis  cylinder,  or  axon,  sur- 
rounded by  one  or  two  protect- 
ing sheaths ;  others  are  composed 
of  the  central  filament  only. 
Nerve  fibers  conduct  impulses 
between  the  various  tissues  and 
organs,  and  nerve  centers.  A 
nerve  fiber  or  axon  then  is  a 
long,  very  slender,  white  or 
grayish  thread,  the  extension  of 
a  nerve  cell. 

A  nerve  is  composed  of  an 
indefinite  number  of  nerve  fi- 
bers supported  within  a  com- 
mon sheath. 

A  nerve  cell  or  neuron  is  an 

irregularly  shaped  microscopic 

cell,  having  a  varying  number 

of  branches,  one  of  which  may 

continue  to   indefinite  length   as  the   axis   cylinder  or   central 

filament  previously  mentioned. 

Nerve  Fibers. — Classified  according  to  function,  nerve  fibers 
are  either :  motor,  sensory,  or  special  sense.  Each  of  these 
conveys  but  one  certain  impulse  and  in  one  direction  only. 

Motor  fibers  are  those  which  convey  impulses  to  the  muscles 
and  control  muscular  action ;  for  example  an  electric  shock,  or 
a  pin  prick  of  a  motor  nerve,  causes  the  muscles  which  it  sup- 
plies to  contract. 

Sensory  fibers  are  those  which  convey  impulses  toward  brain 
centers  and  give  only  sensation  to  the  structures  to  which  they 


NEURON 

(D/a<^rammatic) 


Arborizat/oh 

Fig.  19. 


NERVOUS  SYSTEM 


35 


are  distributed ;  for  example,  irritation  of  a  sensory  nerve  gives 
an  impression  of  pain,  but  no  motion  or  special  sensation. 

Fibers  of  fecial  sense  as  in  olfactory,  optic,  and  auditory 
nerves,  transmit  only  sensations  that  pertain  to  the  functions  of 
the  special  senses  like  hearing 
and  sight.  A  jar  on  the  head 
irritating  the  optic  nerve  gives 
a  sensation  of  flashes  of  light. 
Irritation  of  the  auditory  nerve 
gives  an  impression  of  sound,  etc. 

Many  of  the  cranial  and  all  the 
spinal  nerves  contain  both  motor 
and  sensory  fibers  and  are  there- 
fore mixed. 

Nerves  are  therefore  classified 
as  motor,  sensory,  and  mixed 
nerves,  and  nerves  of  special 
sense  according  to  the  kind  or 
kinds  of  fibers  composing  them. 

The  nervous  system  is  subdivided  for  study  into  the  cerebro- 
spinal and  sympathetic  nervous  systems.  But  these  are  very 
intimately  related  to  each  other.  Working  together  they  con- 
stitute one  united  system. 


Ajc/j   cy/zne/er 


A^ec/t///ary 


A/eur//em  ma 


MEDULLATfD  AffPV£  F/BPE 

Fig.  20. 


Cerebrospinal  System 

The  cerebrospinal  nervous  system  consists  of  the  brain  and 
spinal  cord,  together  with  their  nerves  and  ganglia.  The  brain 
and  spinal  cord  should  be  considered  as  one  complex  organ 
located  within  a  continuous  canal,  the  brain  to  be  considered 
as  merely  an  enlargement  at  the  anterior  extremity.  The 
cranial  cavity  should  be  considered  as  an  enlargement  at  the 
anterior  extremity  of  the  spinal  canal.  The  cranial  bones  may 
be  considered  as  peculiarly  developed  vertebra?. 

Brain. — This  organ  is  located  in  an  ovoid  cavity,  the  walls  of 
which  are  formed  by  the  cranial  bones.  It  is  covered  by  three 
membranes  :  (1)  The  dura  mater  is  tough,  thick,  and  strong,  and 
fitted  to  the  inner  surface  of  the  cranial  bones.  (2)  The 
arachnoid  consists  of  two  layers  forming  a  closed  sack,  the 
outer  layer  fitted  closely  to  the  dura  mater,  and  the  inner  layer 
fitted  closely  to  the  pia  mater.     (3)    The  pia  mater  is  thin, 


36 


VETERINARY  STUDIES 


delicate,  and  fits  closely  to  the  brain  su.bstance — over  the  con- 
volutions and  into  the  depressions. 

Gray  matter,  folded  into  convolutions,  covers  the  surface. 
The  interior  is  composed  of  white  matter. 

Function. — The  physiological  function  of  the  brain  is  to 
receive  messages,  consider  information,  and  send  out  appro- 
priate impulses  or  orders  to  the  proper  organs. 

Divisions. — The  brain  is  divided  for  study  into:  (a)  cerebrum; 
(&)  cerebellum;  (c)  medulla;  (d)  isthmus. 


Fig.  21. — Spinal  Cord  and  Brain  in  Diagram.     (M.  H.  B.) 

1.  Cross  Section  of  the  Spinal  Cord.  A,  superior  median  fissure;  B,  in- 
ferior median  fissure;  C,  C,  superior  gray  horns;  D,  D,  inferior  gray  horns; 
E,  central  canal;  F,  white  substance. 

2.  Vertical  Mid-Section  of  Brain.  A,  medulla;  B,  cerebellum;  C,  pons  or 
bridge;  D,  isthmus;  E,  cerebrum. 


The  cerehnmi,  is  largest,  and  located  in  the  anterior  part 
of  the  brain  cavity,  and  is  divided  into  two  lobes  or  hemispheres 
by  the  median  fissure. 

The  cerehcUwm.,  smaller  than  the  cerebrum,  is  located  in  the 
posterior  and  inferior  part  of  the  brain  cavity,  and  consists  of 
three  small  lobes.  Section  shows  the  arbor- vitaj  (tree  of  life) 
arrangement  of  nerve  tissue.  It  is  the  function  of  the  cerebellum 
to  control  the  voluntary  muscles  that  they  may  work  in  harmony. 

The  medulla  is  a  continuation  of  the  spinal  cord  and  extends 
from  the  occipital  opening  in  the  brain  cavity  to  the  pons  or 
bridge,  and  is  located  posterior  and  inferior  to  the  cerebellum. 

Within  the  medulla  are  located  a  number  of  important  centers, 
among  them  the  ones  controlling  respiration ;  the  caliber  of 
blood  vessels  and  distribution  of  the  blood  according  to  the 
needs  of  the  body ;  the  center  controlling  the  processes  of  swal- 
lowing; the  vomiting  center;  and  the  center  controlling  the 
secretion  of  saliva. 


NERVOUS  SYSTEM  37 

The  isthmus  is  that  part  of  the  inferior  portion  of  the  brain 
which  connects  the  pons  with  the  cerebrum. 

Cranial  nerves. — There  are  twelve  pairs  of  which  the  first 
is  olfactory — smell ;  second,  optic — sight ;  third,  oculo-motor,  to 
several  muscles  which  move  the  eyeball  and  iris,  controlling  in 
part  the  size  of  the  pupil  of  the  eye;  fifth,  trigeminal,  or  tri- 
facial, to  eye,  skin  of  the  face,  teeth,  etc. ;  seventh,  facial,  prin- 
cipally motor  to  muscles  of  face,  mouth,  tongue,  ear,  and  neck; 
eighth,  auditory,  to  internal  ear— hearing;  ninth,  glossopharyn- 
geal to  tongue  and  phars'nx,  sense  of  taste  and  general  sensation ; 
tenth,  vagus,  sometimes  called  the  wandering  pair,  distributed  to 
heart,  lungs,  stomach,  liver,  intestines  and  other  abdominal 
organs.^ 

Spinal  cord. — That  portion  of  the  cerebrospinal  system  which 
extends  within  the  spinal  canal  from  the  occipital  opening  to  the 
sacrum  is  known  as  the  spinal  cord.  It  weighs  about  10.5  ounces 
and  consists  of  white  matter  on  the  outside  and  gray  matter 
in  the  interior,  and  is  covered  by  the  same  three  membranes  as 
the  brain.  The  spinal  cord  is  marked  throughout  its  entire 
length  by  two  fissures,  one  extending  along  the  superior  surface, 
and  another  along  the  inferior  surface. 

It  is  the  function  of  the  spinal  cord  to  act  as  a  means  of 
communication  between  the  brain  and  spinal  nerves,  and  as  a 
reflex  nerve  center. 

Spinal  nerves.— There  are  about  42  pairs.  Each  nerve  has 
origin  in  two  roots.  One  root  (superior)  comes  from  the  upper 
portion  of  the  cord  and  is  composed  of  sensory  fibers.  The 
other  root  (inferior)  comes  from  the  lower  portion  of  the 
cord  and  is  composed  of  motor  fibers.  The  nerve  is  therefore 
mixed. 

These  nerves  emerge  from  the  spinal  canal  in  pairs,  one 
on  each  side  and  at  each  articulation  of  the  vertebrip.  They 
are  named  cervical,  dorsal,  etc.,  according  to  location  in  the 
spinal  column. 

The  spinal  nerves  supply,  by  their  superior  branches,  the 
skin  and  muscles  of  the  neck  and  back  with  both  sensation  and 
motion.  By  their  inferior  branches  they  supply  the  lower 
'The  fourth,  pathetic,  nerves,  and  sixth,  alxhtcens,  are  motor  nerves  to 
other  muscles  of  the  eyeball,  cooperating  with  the  third  in  moving  it.  The 
eleventh,  spinal  accessor]!,  is  also  a  motor  nerve  to  muscles  of  the  head, 
neck,  withers,  arm,  etc  The  twelfth,  hypoglossal,  controls  the  muscles 
of  which  the  tongue  is  largely  composed. 


38 


VETERINARY  STUDIES 


portion  of  the  body  and  limbs  with  both  sensation  and  motion 
and  furnish  other  branches  which  in  part  make  up  the  two 
great  sympathetic  nerve  trunks. 

The   Sympathetic   System 

This  consists  of  tw^o  cords,  one  on  each  side  of  the  spinal 
column,  and  extending  from  the  head  to  root  of  tail,  together 
with  all  the  nerves  which  branch  from  these  two  trunks.  These 
cords  are  not  smooth,  but  have  enlargements  called  ganglia  at 


Fig.   22. — Relation  op  the  Sympathetic   and  Cerebrospinal  Systems. 
Partly  Diagrammatic.     (Chauveau.) 

1,   Brain;    2,   spinal   cord;    3,   sympathetics. 


intervals  along  their  course.  Each  cord  resembles  somewhat  a 
small,  rather  flat,  and  knotted  rope. 

Composition. — These  two  trunks  are  composed  of  nerves 
from  the  medulla  and  from  the  inferior  branches  of  all  the 
spinal  nerves  except  the  coccygeal.  By  this  arrangement  and 
composition,  and  the  frequent  connections  of  sympathetic  with 
cerebrospinal  nerves,  there  is  constituted  a  very  perfect  union  of 
these  two  into  one  gi'eat  nervous  system. 

Ganglia. — The  knots  along  the  two  main  trunks  are  ganglia 
of  nerve  cells  and  fibers.  One  of  these,  the  solar  plexus,  is 
really  composed  of  two  large  ganglia,  united  by  a  large  cord 
and  many  filaments.  It  supplies  the  stomach,  intestines,  liver, 
pancreas,  spleen,  and  kidneys.  An  injury  to  the  solar  (coeliac) 
plexus  is  always  serious. 


NERVOUS  SYSTEM  39 

Sympathetic  nerves. — These  control,  in  part,  involuntary 
muscle  fibers  and  through  these  the  organs  of  circulation,  respira- 
tion, and  digestion,  the  size  of  the  pupil  of  the  eye,  and  the 
work  of  the  various  glands  including  the  liver,  spleen,  pancreas, 
and  kidneys. 

Practical  application. — Summarizing,  we  may  say  that  the 
cerebrospinal  nervous  system  controls  the  muscles  of  the  skeleton 
(lean  meat),  gives  sensation  to  skin  and  skeletal  muscles,  and 
the  special  sensatioiLs  of  sight,  hearing,  taste,  smell,  etc. 

The  sympathetic  nervous  system  controls  the  involuntary 
muscle  fibers  of  the  blood  vessels,  increasing  or  decreasing  their 
capacity  as  needed;  it  controls  the  involuntary  muscle  fibers  of 
the  digestive  organs,  such  as  the  stomach  and  intestines,  produc- 
ing the  necessary  motion  automatically;  it  controls  the  move- 
ments and  work  of  the  bladder,  the  movements  of  the  hair,  and 
the  involuntary  muscle  fibers  of  the  iris  (colored  portion  of  the 
eye) ,  making  the  pupil  large  or  small,  according  to  the  intensity 
of  light.  Directly  or  indirectly  the  sympathetic  nerves  also 
control  in  part  the  work  of  secretion  and  excretion  in  the 
salivary  glands,  liver,  kidneys  and  other  organs. 

The  student  should  now  make  practical  observations.  He 
may,  for  example,  record  past  experience  or  present  observations 
concerning  horses  and  cattle,  taking  those  of  sluggish,  well 
balanced,  and  highly  nervous  organizations.  Compare  these 
different  types  as  to  working  efficiency,  feeding,  and  keeping. 
Quiet  steers  do  better.  AVhat  is  the  physiological  explanation? 
Note  the  effect  of  excitement  on  high  type  dairy  cows  as  to 
production — quantity  and  quality  of  milk  considered.  What  is 
the  explanation?  Wiiat  connection  between  excitement  in  the 
brain  and  milk  in  the  udder? 

In  making  these  studies,  bear  in  mind  that  the  quantity  and 
quality  of  digestive  fluids,  food  absorption,  distribution  and 
utilization  of  food  material,  the  amount  of  blood  flowing  through 
a  cow's  udder,  and  the  degree  of  gland  cell  activity  in  the  udder 
are  all  under  the  direct  influence  of  the  nervous  system. 

Disorders  of  the  nervous  system  are  often  complicated  and 
difficult  to  handle.  Veterinary  services  are  usually  necessary. 
The  following  are  typical  disorders  which  the  stockman  should 
understand  in  a  general  way.  It  is  important  to  understand 
that  nerve  tissue  is  subject  to  the  same  actual  disease  changes  as 
other  tissues — atrophy,  congestion,  inflammation,  and  degenera- 


40  VETERINARY  STUDIES 

tion,  for  example — and  that  these  changes  interfere  with  normal 
function. 

Posterior  paralysis  of  swine  is  of  many  types,  due  to  several 
different  causes  and  characterized  by  partial  or  complete  motor 
paralysis  of  the  hind  quarters. 

Milk  fever  (poorly  named)  is  a  common  disorder  of  cows  at 
calving  time,  characterized  by  both  motor  and  sensory  paralysis, 
loss  of  consciousness,  etc.  (See  Lecture  XLIX.)  Treated  by 
pumping  the  udder  full  of  air  and  giving  hypodennic  stimu- 
lants when  necessary. 

Stringhalt,  or  spring  halt,  is  a  peculiar  affection  usually  of 
one  or  both  hind  legs,  characterized  by  a  sudden  jerking  of  the 
limb  upward.  Treatment  by  a  veterinary  surgical  operation 
cures  in  some  cases. 

Rahies  (hydrophobia)  is  a  serious  disorder  of  the  nervous  sys- 
tem, usually  produced  by  inoculation  from  the  bite  of  an  affected 
animal— usually  a  dog— the  virus  being  in  the  saliva.  This  is 
characterized  in  the  dog  by  unnatural  affection  at  first,  then  by 
a  tendency  to  run  away  from  home,  biting  animals  or  people 
en  route,  then  paralysis  of  the  lower  jaw  and  tongue,  hoarse, 
unnatural  bark,  and  death.  Some  cases  are  mild,  quiet,  and 
deceptive.  Treatment  of  bitten  person  by  prompt  vaccination 
is  a  reasonably  certain  preventive.  Animals  that  have  been 
bitten  should  be  killed  or  securely  confined  for  a  month  or  more. 

Facial  paralysis  is  usually  due  to  paralysis  of  the  7th  cranial 
nerve,  and  is  indicated  by  a  drawing  of  the  lips  toward  the 
sound  side. 

Tetanus  (lock  jaw)  affects  various  domestic  animals  and 
people.  It  is  caused  by  inoculation  with  a  bacillus  common  in 
garden  earth,  and  is  characterized  by  tense,  persistent  contrac- 
tion of  the  voluntary  muscles,  including  those  of  the  jaws;  by 
a  spasmodic  movement  over  the  eyeball  of  a  membrane  often 
called  the  haw  or  third  eyelid  (properly  the  nectitating  mem- 
brane). It  is  frequently  fatal,  but  can  usually  be  prevented  by 
prompt  injection  of  large  doses  of  anti-tetanic  serum  soon  after 
an  injury,  for  example  a  nail  puncture  in  the  foot. 

Over  heat,  often  called  sunstroke,  is  either  an  exhaustion  of 
the  temperature  regulating  nerve  machinery  or  an  overwhelm- 
ing  of  the  nervous  system  by  an  excessive  accumulation  of  heat 
within  the  body.  It  is  most  apt  to  affect  the  animal  that  is  out 
of  condition  for  heat  and  exercise,  or  the  hoi-se  that  has  been 


NERVOUS  SYSTEM  41 

overheated  before  or  one  that  is  already  slightly  ailing  when 
going  to  Avork.  Over  heat  is  characterized  by  lagging  in  harness, 
undue  i)anting,  and  sudden  cheek  of  perspiration,  very  high 
fever,  livid  mucous  membranes,  rapid,  weak  pulse,  and  difficult 
respiration. 

Stop  work  at  the  first  warning;  get  the  horse  to  shade, 
sprinkle  cold  water  over  the  body,  especially  back  and  head, 
or  apply  ice  pack  to  head  and  cold  water  over  the  body  until 
his  temperature  reaches  about  104  degrees;  then  stop.  Give 
stimulants,  e.g.,  aromatic  ammonia  if  the  horse  can  swallow 
easily;  or  a  hypodermic  injection  of  40-60  grains  camphor  dis- 
solved in  olive  oil  1-4.     Call  veterinarian  promptly. 

Forage  poisoning  has  apparently  been  identified  with  "food 
poisoning"  (botulism)  in  people.  The  symptoms  differ  with  the 
severity  of  attack  and  in  difl'erent  classes  of  animals ;  it  is  most 
common  in  horses  and  is  very  often  associated  with  mouldy 
feed,  this  being,  perhaps,  a  secondary  factor.  The  specific  cause 
appears  to  be  Bacillus  hotulinus.  This  disorder  is  characterized 
by  plain  disturbances  of  the  nervous  system,  which  involve  espe- 
cially sensory  nerves  and  motor  nerves  to  the  muscles  of  head, 
neck,  and  limbs.  There  is  often  a  peculiar,  sweetish  odor  in 
the  breath,  and  an  inability  to  swallow  normally.  The  animal 
is  dull  or  excited,  and  stands  in  a  peculiar  attitude  or  moves 
imperfectly.  Coma  (stupor)  or  sometimes  violent  struggling 
is  common  in  later  stages.    Mortality  is  high. 

Change  feed,  and  physic.  At  present  there  is  an  encouraging 
prospect  for  an  antiserum. 


LECTURE  IX 
CIRCULATION 

Blood. — This  is  a  complex  fluid  consisting  of  serum,  fibrin 
factors,  and  two  kinds  of  corpuscles — the  red  and  the  white. 

Serum  is  the  watery,  straw-colored,  fluid  portion  of  the  blood 
less  the  fibrin  (clot)  factors.  It  contains  various  nutrient  and 
waste  materials,  including  oxygen  and  carbon  dioxid  gases, 
mineral  matters  and  many  inorganic  compounds. 

The  fibrin  factors  are  fibrinogen  and  an  enzyme.  AVhen  blood 
is  exposed  to  the  air  or  comes  in  contact  with  a  foreign  surface, 
the  fibrinogen  is  changed  by  an  enzyme  (thrombin)  and  forms 
tiny  threads  of  fibrin  of  which  the  clot  is  composed.  Red  cor- 
puscles are  entangled  in  the  meshes,  giving  the  red  color. 

Red  corpuscles  are  tiny  discs,  resembling  in  shape  silver  dollars 
with  the  sides  slightly  concaved.  Human  corpuscles  are  about 
1/3200  of  an  inch  in  diameter.  About  six  in  a  row  could  be 
placed  across  the  end  of  a  fine  hair.  They  are  born  in  the  red 
marrow  of  the  bones,  and  die  principally  in  the  blood  stream 
and  spleen.  Apparently  their  chief  function  is  to  carry  oxygen 
from  the  lungs  to  the  tissue  cells. 

White  corpuscles  (leucocytes)  are  much  fewer  in  number,  and 
are  of  several  kinds,  most  of  them  larger  than  the  red  corpuscles. 
They  have  the  power  of  independent  movement  and  may  change 
their  own  shape.  The  ratio  in  the  blood  of  the  horse  is  about 
1  white  to  500  red.  White  cells  have  their  birth  in  various  tis- 
sues, like  lymph  gland,  or  adenoid  tissue  and  bone  marrow,  and 
some  probably  in  the  blood  stream.  Leucocytes  have  several 
very  important  duties,  such  as  destroying  disease-producing 
bacteria  and  aiding  in  the  formation  of  blood  clot  and  the  ab- 
sorption and  distribution  of  fat  as  a  nutrient.  The  temperature 
of  the  blood  in  the  various  domestic  animals  ranges  from  101 
to  104°F.  In  the  horse  it  varies  from  100°  to  101.5°  ;  in  the 
cow  it  is  about  1  degree  higher;  in  sheep  it  is  from  100°  to 
104°.    Its  specific  gravity  is  about  1060,  and  it  constitutes  about 

1/15  the  body  weight. 

42 


CIRCULATION 


43 


Summing  up  the  functions  of  blood,  we  may  say  that  it 
distributes  nutrient  materials  and  oxygen.  It  drains  the  tissues 
of  their  waste,  poisonous  and  useless  materials.  It  serves  as  a 
means  of  intimate  connection  between  organs,  e.g.,  as  by  con- 
veyance of  internal  secretions  produced  by  one  organ  and 
needed  as  a  necessary  stimulant  for  the  work  of  another  organ. 


Fig.  23. — Circulation.     Arteries  Gray,  Veins  White. 

1,  Heart,  right  ventricle;  2,  left  ventricle;  3,  left  auricle;  4,  pulmonary 
artery;  5,  pulmonary  veins;  6,  anterior  aorta;  7,  carotid  artery;  9,  left 
maxillary  artery;  13,  humeral  artery;  14,  radial  artery;  15,  metacarpal 
artery;  16,  digital  artery;  17,  posterior  aorta;  18,  coeliac  trunk;  19, 
mesenteric  trunk;  20,  renal  (kidney)  artery;  22,  posterior  vena  cava  (vein)  ; 
23,  portal  vein;  24,  external  iliac  artery;  25,  internal  iliac  artery;  27, 
femoral  artery;  28,  posterior  tibial  artery;  29,  metatarsal  artery;  30,  venous 
supply  to  the  foot;  33,  jugular  vein. 

It  serves  as  a  hot  water  heat  circulating  plant,  carrying  surplus 
heat  from  actively  working  organs  like  voluntary  muscles  and 
heart,  where  much  heat  is  produced,  and  from  internal  organs 
where  heat  loss  is  low,  to  skin  and  extremities,  where  the  heat 
loss  is  rapid. 

Circulatory  apparatus. — Heart,  arteries,  veins,  capillaries, 
lymph  spaces,  lyinpliatic  vessels,  and  lymph  glands  constitute 
the  circulatory  apparatus. 


44 


VETERINARY  STUDIES 


Heart. — The  heart  is  enclosed  by  a  serous  sac,  the  pericardium, 
which  supports  it  in  place  beneath  the  third,  fourth  and  fifth 
dorsal  vertebra?  by  attaching  to  the  large  blood  vessels  at  its 
base,  to  the  diaphragm  behind,  and  to  the  sternum  below.  The 
horse's  heart  measures  about  10.5  inches  in  length  by  7.5  wide 
at  the  base,  and  is  cone-shaped ;  the  weight  is  variable  but  aver- 


FiG.  24. — Circulation.    Diagrammatic. 

1.  Heart  and  Blood  Vessels.    A,  Heart;  B,  pericardium;  C,  anterior  vena 
cava ;  D,  posterior  vena  cava ;  E,  anterior  aorta ;  F,  posterior  aorta. 

2.  The   Circulation   in   Diagram.      A,  A,   auricle-ventricle   valves;    B,    B, 
semilunar  valves. 


ages  about  nine  pounds.  The  heart  contains  four  cavities  which 
are  easily  seen  when  it  is  cut  open.  The  two  located  at  the  base 
are  called  auricles;  and  the  two  at  the  apex,  ventricles. 

The  auricles  are  much  alike ;  as  are  also  the  ventricles,  except 
that  the  left  ventricle  is  larger  and  has  a  wall  which  is  more  than 
twice  as  thick  as  the  right.  The  heart  is  covered  by  the  peri- 
cardium and  lined  with  the  endocardium.  Its  muscle  fibers  are 
involuntary  so  far  as  control  is  concerned,  but  are  striped. 


CIRCULATION 


45 


The  opening  between  the  right  auricle  and  the  right  ventricle 
is  guarded  by  the  right  auriculo-ventricular  (tricuspid)  valve; 
the  opening  between  the  right  ventricle  and  the  pulmonary  ar- 
tery is  guarded  by  the  right  semilunar  valve. 

The  opening  betAveen  the  left  ventricle  and  the  left  auricle  is 
guarded  by  the  left  auriculo-ventricular  (bicuspid)  valve,  and 
the  opening  to  the  aorta  from  the  left  ventricle  is  guarded  by 


Fig.  25. — Capillary  Circulation.      (Eddy.) 

In  the  web  of  a  frog's  foot  (X  100)  ;  a,  b,  small  veins;  d,  capillaries  in 
which  the  corpuscles  are  seen  to  follow  one  another  in  single  series;  c, 
pigment  cells  in  the  skin. 


the  left  semilunar  valve.  Valves  at  these  places  are  necessary  to 
prevent  tlie  blood  from  moving  backward  instead  of  forward. 
Course  of  the  blood. — Entering  the  right  auricle  of  the  heart 
through  two  large  veins,  the  anterior  and  posterior  vena  cavip, 
and  the  coronary  vein,  the  blood  passes  through  this  auricle 
into  the  right  ventricle,  thence  to  the  lungs,  through  the  pul- 
monary artery  back  to  the  left  auricle,  through  four  to  eight 
pulmonary  veins,  past  the  valves  on  the  left  side,  and  finally  to 
the  left  ventricle  which  sends  it  through  the  systemic  circuit. 
The  systemic  blood  leaves  the  left  ventricle  through  a  large 
artery,  the  aorta,  which  distributes  blood  through  its  branches  to 
all  parts  of  the  body. 


46  VETERINARY  STUDIES 

The  pulmonary  circulation  is  the  flow  of  blood  which  occurs 
betw-een  the  heart  and  the  lungs. 

The  systemic  circulation  is  that  which  occurs  between  the 
heart  and  all  the  rest  of  the  body,  except  the  lungs. 

Arteries,  veins  and  capillaries. — These  are  elastic  tubes  which 
distribute  blood  to  the  tissues  and  then  collect  and  convey  it 
back  to  the  heart.  Arteries  have  thicker  and  more  elastic  walls 
than  veins ;  they  remain  open  after  death  although  empty ;  the 
stream  flows  in  jets;  the  l)lood  is  lighter  in  color  than  that  in 
the  veins  and  flows  from  the  heart  and  they  have  no  valves.  In 
all  these  points,  the  arterial  system  differs  from  the  venous. 
Both  arteries  and  veins  consist  of  three  coats:  outer,  fibrous; 
middle,  muscular ;  inner,  serous. 

Capillaries  are  the  small  vessels  which  connect  minute  arteries 
with  minute  veins.  They  are  generally  about  one  twenty-fifth 
of  an  inch  in  length,  and  one  twenty-five-hundredth  of  an  inch 
in  diameter. 

Blood  Supply  op  the  Body 

Arteries. — The  aorta  is  the  trunk  artery  which  receives  blood 
from  the  left  ventricle  for  distribution  through  the  systemic  cir- 
cuit to  practically  the  entire  body  except  the  lungs;  i.e.  except- 
ing the  pulmonary  circuit.  It  is  about  two  inches  long  and 
branches  into  two  large  trunks,  the  anterior  aorta  and  the  pos- 
terior aorta.  The  anterior  aorta  supplies  the  head,  neck,  and 
front  limbs ;  and  the  posterior  supplies  nearly  all  the  rest  of  the 
body. 

The  anterior  aorta  is  smaller  and  shorter  (one  inch  long)  than 
the  posterior.  Its  course  is  upward  and  forward.  It  branches 
into  the  right  and  left  axillary  arteries.  These  lie  near  the 
trachea,  one  on  each  side,  for  a  short  distance,  and  then  bend 
around  the  anterior  borders  of  the  first  ribs  and  terminate  at  the 
inner  part  of  each  shoulder  in  the  humeral  arteries  (right  and 
left),  which  are  the  continuing  branches  of  the  axillary.  Each 
humeral  furnishes  blood  for  the  corresponding  front  limb. 

The  common  carotid  arteries,  right  and  left,  have  their  origin 
in  a  single  vessel,  the  cephalic  artery,  which  branches  from  the 
right  axillary  near  the  division  of  the  anterior  aorta  into  right 
and  left  axillary  arteries.  They  supply  structures  in  the  neck 
and  head. 

A  corpuscle,  on  its  way  from  the  heart  to  the  brain,  would 


CIRCULATION  47 

pass  through  the  aorta,  anterior  aorta,  right  axillary,  cephalic, 
and  common  carotid,  and  then  through  a  branch  of  the  carotid 
to  the  brain,  each  of  these  arteries  being  a  branch  of  the  preced- 
ing. 

The  posterior  aorta  curves  upward  and  backward,  through  the 
diaphragm,  then  under  the  bodies  of  the  dorsal  and  lumbar 
vertebras  to  the  lumbo-sacral  articulation.  This  large  artery 
supplies  blood  to  the  thoracic  and  abdominal  organs  and  trunk, 
and  tlien  terminates  in  four  branches  named  iliacs, — two  exter- 
nal and  two  internal. 

The  two  cxterniil  iliacs  correspond  somewhat  to  the  two  axil- 
laries  in  front  and  the  two  femoral  arteries  to  the  two  humeral, 
for  it  is  the  femoral  arteries  which  continue  the  external  iliacs 
and  distribute  blood  to  the  posterior  limbs  and  feet. 

The  two  internal  iliacs  are  smaller  and  distribute  blood  to  the 
pelvic  organs. 

Veins.— Veins  collect  and  return  the  blood  distributed  by  the 
arteries  and  usually  accompany  the  arteries.  One  large  vein 
commonly  accompanies  each  large  artery,  and  two  small  veins 
accompany  each  of  the  smaller  arteries;  but  this  course  is  not 
invariable. 

The  anterior  vena  cava  corresponds  to  the  anterior  aorta  and 
the  posterior  vena  cava  to  the  posterior  aorta.  Each  returns  the 
blood  to  the  heart  which  its  corresponding  aorta  has  distributed. 

All  the  veins  except  those  of  the  bones,  small  veins  in  the  feet, 
and  the  veins  of  the  brain  and  spinal  cord,  have  valves. 

Valves  are  most  common  and  numerous  in  the  veins  of  the 
extremities  and  in  those  veins  which  pass  through  and  between 
voluntary  muscles. 

Pulmonary  veins,  four  to  eight  in  number,  have  their  origin  in 
many  small  branches  within  the  lungs.  They  return  blood  from 
lungs  to  heart  in  the  pulmonary  circuit,  and  carry  pure  blood. 

The  anterior  vena  cava  has  its  origin  between  the  two  first 
ribs  at  the  juncture  of  the  two  jugular  and  two  axillary  veins. 
Jugular  vein  corresponds  to  carotid  artery,  and  axillary  vein  to 
axillary  artery^ 

The  posterior  vena  cava  has  its  origin  near  the  last  lumbar 
vertebra  at  the  union  of  the  common  iliac  veins.  It  passes  be- 
neath and  at  one  side  of  the  bodies  of  the  vertebra?,  through 
liver  and  diaphragm,  and  discharges  its  blood  into  the  right 
auricle  of  the  heart. 


48 


VETERINARY  STUDIES 


Lymphatic  System 


Parts. — The  lymphatic  system  consists  of  vessels  and  glands. 
Lymphatic  vessels. — These  have  thin  transparent  walls  and 

are  found  in  most  of  the  body 
tissues.  They  have  valves  like 
the  veins  and  carry  lymph,  or, 
in  the  lacteals,  chyle.  The  cur- 
rent in  the  lymph  vessels  is  like 
that  in  the  veins  in  that  it  flows 
toward  the  heart  and  is  very  slug- 
gish. The  lacteals  are  lymphatic 
vessels  which  drain  the  digestive 
canal,  chiefly  the  small  intestines. 
There  are  two  main  vessels :  the 
thoracic  and  right  lymphatic. 

The  thoracic  is  situated  near 
the  vertebral  column  within  the 
abdomen  and  thorax,  on  the  right 
side,  near  the  heads  of  the  ribs 
and  discharges  its  lymph  into  the 
anterior  vena  cava.  Its  opening 
in  the  vein  is  protected  by  a  valve 
in  order  that  blood  may  not  get 
into  the  duct.  This  duct  drains 
all  the  body  except  the  right  side 
of  the  face,  head,  and  neck,  the 
right  shoulder,  and  the  right 
front  limb. 

The  right  lymphatic  duct  is 
not  always  present  in  typical 
form.  When  present  it  is  a  very 
short  vessel  into  w'hich  empty 
all  the  vessels  that  drain  these 
latter  regions.  It  discharges  into 
the  anterior  vena  cava  with  or 
near  the  thoracic  duct. 
Lymph  glands.— The  lymph  glands  serve  in  part  to  remove 

from  the  lymph  fluid  disease  germs  and  other  harmful  bodies. 

Their  structure  and  function  is  something  like  that  of  a  sponge 

filter. 


Fig,    26. — The   Lymphatic   Sys- 
tem.    Human.     (Eddy.) 

a,  Union  of  left  jugular  and 
subclavian  veins,  ami  point  of 
union  with  the  thoracic  duct ; 
h,  thoracic  duct ;  c,  right  jugular 
and  subclavian  veins,  and  point 
of  union  of  right  lymphatic  sys- 
tem ;  d,  receptacle  for  food  ab- 
sorbed from  the  intestine;  the 
oval  bodies  are  glands. 


CIRCULATION 


49 


Function. — The  lymph  fluid  is  essentially  the  blood  minus  the 
red  blood  corpuscles.  The  general  fluid  movement  is  from  blood 
capillaries  into  lymph  spaces,  then  lymph  vessels,  and,  finally, 
back  to  the  blood  of  the  anterior  vena  cava.  The  lymph  fluid 
distributes  nourishment  by  osmosis  directly  to  the  body  tissues, 
and  removes  waste  materials  by  the  same  process.  For  example, 
in  the  lymph  fluid  held  by  the  lymph  spaces  of  the  cows'  udder 
and  very  close  to  the  milk-gland  cells,  are  the  food  materials 
from  which  the  gland  cells  may  manu- 
facture the  casein,  fat,  sugar,  and 
other  ingredients  of  milk.  The  nutri- 
tious materials  are  as  a  rule  taken  into 
the  lymph  from  the  blood,  and  waste 
materials  which  the  lymph  receives 
from  the  tissues  are  poured  into  the 
blood  through  the  thoracic  duct  and 
the  right  lymphatic  duct. 

Practical  application. — The  student 
should  see  in  the  circulation  something 
more  than  a  collection  of  technical 
terms  and  abstract  theories  concern- 
ing the  physics  of  circulation. 

The  blood  serves,  in  a  general 
way,  as  a  wholesale  distributor  of 
needed  materials  to  the  tissues,  and 
as  a  wholesale  collector  of  waste  and 
poisonous  substance  from  the  tissues. 
The  lymph  fluid  is,  in  a  general  way, 
the  retail  distributor  and  collector; 
and  the  two,  after  all,  constitute  one 

circulation  system,  the  lymph  being  the  watery  portion  of  the 
blood,  plus  white  corpuscles.  It  comes  into  the  tiny  lymph  spaces 
from  the  capillaries  and  returns  to  the  large  vein  (anterior  vena 
cava)  through  two  large  lymph  vessels,  the  right  lymphatic  and 
the  thoracic.  The  entire  circulatory  system  has  an  intimate  and 
important  part  in  all  disease  processes,  such  as  congestion,  inflam- 
mation, tissue  degeneration,  and  restoration  after  inflammation. 
An  abundant  circulation  through  the  dairy  cow's  udder  makes 
possible  the  production  of  a  large  quantity  of  milk.  A  disturb- 
ance in  the  circulation  of  a  human  brain  causes  a  person  to 
faint  and  fall. 


Fig.  27. — A  Lymph  Node. 
(Eddy.) 


50  VETERINARY  STUDIES 

Disorders  of  circulation  and  diseases  of  the  organs  of  circula- 
tion are  numerous  and  of  great  importance,  but  too  complicated 
and  difficult,  as  a  rule,  for  the  stockman  to  handle.  The  heart, 
blood  vessels,  lymph  vessels,  and  lymph  glands  are  often  involved 
in  disease.  The  heart  may  undergo  a  fatty  degeneration,  or  it 
may  dilate,  or  the  valves  become  diseased  and  fail  to  cloce  their 
openings.  Arteries  may  become  thin  and  weak,  and  dilate 
greatly  (aneurism),  or  become  inflamed,  degenerate  and  become 
brittle,  and  then  rupture  (calcareous  degeneration).  Capil- 
laries may  be  injured  by  toxic  substances  in  the  blood,  then  leak 
or  rupture  (tissue  hemorrhage).  Veins  become  inflamed  or  the 
venous  wall  may  weaken  and  stretch,  resulting  in  varicose  veins. 

Lymph  vessels  and  glands  may  become  infected  by  bacteria, 
then  inflamed  and  swollen.  The  glands  often  suppurate,  and 
are  destroyed  after  infection  by  the  bacteria  of  tuberculosis, 
glanders,  etc.  Ordinary  "weed"  or  "elephant  leg"  (lymphan- 
gitis) is  a  good  example  of  disease  of  lymph  vessels  and  glands. 
This  disease  of  horses  is  characterized  by  chill,  then  fever,  and 
sudden  swelling  of  one  hind  leg  on  the  inside  and  high  up.  This 
swelling  extends  around  the  leg  and  down  to  the  foot.  After 
the  inflammation  subsides,  the  limb  is  left  larger  than  normal. 
Both  lymph  vessels  and  lymph  glands  are  involved  and  the 
disease  is  apt  to  recur,  each  time  leaving  the  leg  larger  than 
before. 


LECTURE  X 
RESPIRATION 

Respiration  is  the  process  by  which  the  tissues  gain  oxygen 
and  give  off  impurities.  This  process  is  controlled  by  the  res- 
piratory center,  a  group  of  nerve  cells  located  in  the  medulla, 
a  portion  of  the  brain.  Fibers  from  these  cells  form  part  of  the 
tenth  cranial  (vagus)  nerve  to  the  lungs  and  respiratory 
muscles.  This  respiratory  nerve  mechanism  is  stimulated  by  the 
presence  of  CO.  in  the  blood,  or  by  lack  of  oxygen ;  v^hereas,  it 
is  inhibited  (restrained)  by  oxygen  and  thus  the  needed  rate 
of  respiration  is  maintained.  Apparently,  the  plain  simple  pur- 
pose of  respiration  is  twofold :  ( 1 )  to  get  oxygen  into  the  blood 
and  various  body  tissues,  and  (2)  to  get  carbonic  gas  (CO,) 
and  various  other  organic  impurities  out  of  the  blood  and  body 
tissues.  It  is  a  common  mistake  to  suppose  that  respiration  is 
confined  to  the  lungs.  A  very  important  portion  of  the  true 
respiration  occurs  between  the  blood  and  individual  tissue  cells 
apart  from  the  lungs. 

Respiration  includes  oxidation  and  also  elimination  of  waste 
products.  This  involves  a  double  series  of  exchanges,  one  series 
occurring  in  the  lungs  and  a  reversed  series  occurring  mainly 
in  the  tissue  cells.  All  tissues  and  even  the  blood,  when  func- 
tioning, consume  oxygen  and  form  carbon  dioxid. 

Continuous  oxidation  processes  in  the  body  result  in  contin- 
uous production  of  carbonic  acid  gas,  urea,  water,  and  other 
waste  products. 

Stag"es. — There  are  four  stages  in  the  complete  act  of  respi- 
ration: {a)  air  comes  into  the  lungs;  (6)  blood  takes  out  part 
of  the  oxygen;  (c)  tissues  take  part  of  the  oxygen  away  from 
the  blood  and  give  back  to  the  blood  carbonic  gas  and  other  ma- 
terials in  exchange;  and  (d)  the  blood  trades  off  its  carbonic  gas 
and  other  materials  to  the  air  for  oxygen. 

Oxygen  is  carried  to  the  tissues  by  the  blood,  and  waste  prod- 
ucts are  washed  away  from  the  tissues  by  the  same  fluid. 

The  blood  cannot  unite  with  sufficient  oxygen  or  eliminate  its 

51 


52 


VETERINARY  STUDIES 


waste  materials  unless  it  is  brought  in  contact  with  air.  It  is 
in  the  lungs  that  the  red  blood  cells  and  serum  load  up  with 
oxygen,  and  it  is  here  that  carbon  dioxid  gas  (CO,)  and 
other  volatile  impurities  are  eliminated  from  the  blood.  The 
water,  CO,,  and  other  volatile  compounds  in  the  blood  capil- 
laries, and  oxygen  in  the  inspired  air,  are  separated  in  the  lungs 
by  a  thin  animal  membrane.  Nature  is  constantly  endeavoring 
there  to  equalize  pressures  and  satisfy  chemical  affinities  be- 
tween free  gases  on  one  side  of  this  membrane  and  gases  held 
by  a  liquid  on  the  other  side  of  this  same  membrane. 


i/VATER 


OXYGEN 


HEAT 


CARBON  -  Dl-  OX/Dt 


LUNGS 


BLOOD 


GA5 


BODY  T/SSUf^ 


Fig.  28. — Eespiration  in  Diagram.     (M.  E.  E.) 


Aside  from  chemical  combination,  each  gas  moves  either  way 
according  to  the  partial  pressure  of  the  gas  on  one  side  and  the 
tension  of  the  same  gas  in  the  liquid  on  the  other  side  of  this 
membrane.  The  tension  of  the  oxygen  in  venous  blood  is  much 
lower  than  oxygen  pressure  in  lung  air.  The  tension  of  COg 
in  the  venous  blood  is  much  higher  than  its  pressure  in  the  lung 
air.  These  variations  in  pressures  and  tensions  do  not  appear 
to  account  for  all  exchange.  The  living  tisslie  cells  appear  to 
have  a  part  and  probably  interfere  with  the  perfect  working  of 
these  forces  and  a  portion  of  the  CO,  is  carried  as  carbonate 
and  bicarbonate  of  soda. 

The  factors  that  vary  the  proportion  of  oxygen  consumed 
and  CO,  excreted  are:  body  weight,  amount  of  body  surface, 
also  rate  and  depth  of  respiration.  We  have  the  lowest  rate  of 
respiratory  change  in  the  body  during  fasting  and  highest  rate 
on  a  nitrogenous  diet. 

The  amount  of  oxygen  absorbed  and  CO,  developed  increase 


RESPIRATION  53 

rapidly  with  increase  of  body  temperature,  as  in  fever,  and  also 
with  physiological  activity.  iNluscular  activity  greatly  increases 
oxygen  consumption.  Physiologists  tell  us  that  even  shivering 
multiplies  the  respiratory  changes  by  two,  and  that  external 
cold  has  a  similar  effect. 

Parts. — Tlie  respiratory  system  consists  of  nasal  chambers, 
pharynx,  larynx,  trachea,  bronchi,  and  lungs.  These  organs 
are  all  lined  with  mucous  membrane.  This  whole  system  is 
merely  a  device  to  bring  a  thin  sheet  of  blood  into  close  rela- 
tion with  a  sheet  of  air  which  has  the  needed  oxygen.  In  other 
words  its  function  is  to  bring  blood  and  air  so  near  each  other 
that  the  exchange  may  be  rapid  and  the  blood  take  away  oxygen 
and  leave  waste  matters. 

Nostrils. — Two  in  number.  These  are  openings  at  the  front 
of  the  nasal  cavities.  The  skin  covering  the  nostrils  is  compara- 
tively thin,  quite  sensitive,  and  supported  by  cartilages. 

The  inferior  turbinated  bones,  two  in  number,  and  scroll 
shaped,  are  located  on  the  outer  wall  of  each  nasal  cavity. 
Apparently  they  are  there  for  the  purpose  of  warming  cold  air 
by  their  \ery  rich  blood  supply  and  also  provide  a  favorably 
shaped,  moist  surface  to  catch  dust  and  bacteria,  on  their  way 
to  the  lungs. 

Nasal  cavities. — Two  in  number,  one  on  each  side  of  a  median 
partition.  This  partition  is  composed  of  the  vomer,  a  portion 
of  the  ethmoid,  and  the  median  cartilage.  Each  cavity  connects 
in  front  with  the  outside  air  through  the  nostril  and  behind  with 
the  pharynx  through  an  opening  which  may  be  called  the  pos- 
terior nostril  or,  technically,  the  posterior  nares.  Each  cham- 
ber also  connects  laterally  with  the  sinuses  of  the  head  (shown 
in  class).  The  floor,  roof,  and  sides  are  formed  by  the  various 
face  bones,  together  with  portions  of  the  frontal,  ethmoid,  and 
sphenoid,  and  the  median  cartilage  already  mentioned.  The 
mucous  membrane  lining  the  nasal  chambers  is  divided  for  study 
into  two  portions:  the  upper,  the  olfactory,  in  which  are  dis- 
tributed the  terminations  of  the  olfactory  nerves,  and  the  lower, 
the  Schneiderian. 

Pharynx. — This  is  a  muscular  sac  situated  beneath  the 
cranium,  and  back  of  the  soft  palate  which  constitutes  a  par- 
tition between  the  pharynx  and  mouth  cavities.  This  organ 
belongs  to  both  the  respiratory  and  digestive  systems.  Its  walls 
are  composed  of  two  coats:  the  inner  mucous  and  outer  mus- 


54  VETERINARY  STUDIES 

cular.  It  connects  by  openings  with  the  nasal  chambers  above, 
with  the  mouth  in  front,  and  with  the  esophagus  behind,  with 
the  lungs  below,  and  on  each  side  with  the  Eustachian  tube  to 
the  middle  ear. 

Larynx. — A  cartilaginous  box  located  at  the  upper  end  of  the 
trachea  and  composed  of  five  pieces — one  epiglottis,  one  thyroid, 
two  arytenoids,  one  cricoid.  Twelve  muscles  attach  to  these 
cartilages  for  the  purpose  of  controlling  them. 

The  epiglottis  is  a  tongue-shaped  piece  of  flexible  cartilage 
which  aids  in  preventing  food  from  entering  the  larynx  during 
the  act  of  swallowing  and  then  opens  during  respiration. 

The  thyroid  cartilage  (shield-like)  is  located  at  the  upper  and 
front  portion  of  the  larynx,  extending  well  around  on  the  sides. 

The  arytenoids  are  two  in  number,  one  on  each  side.  The  two 
taken  together  are  shaped  somewhat  like  the  front  part  of  a 
pitcher,  situated  at  the  sides  of  the  upper  part  of  the  larynx, 
coming  together  at  the  median  line.  These  cartilages  give  attach- 
ments to  the  vocal  cords.  One  of  these  cartilages,  usually  the 
left,  is  paralyzed  in  the  disease  of  horses  which  is  known  as 
roaring. 

The  cricoid  is  shaped  like  a  ring  with  a  process  on  the  upper 
and  front  part  which  causes  this  cartilage  to  resemble  a  seal 
ring.  It  is  located  at  the  lower  portion  of  the  larynx  and  con- 
nected with  the  trachea. 

The  vocal  cords  are  a  pair  of  narrow  fibrous  bands  so  situated 
as  to  include  a  narrow  triangular  space  between  them.  They 
are  attached  in  front  to  the  thyroid  and  behind  to  the  aryte- 
noids. 

Trachea,  or  windpipe. — This  is  located  beneath  and  in  front 
of  the  esophagus.  It  is  a  long  tube  composed  of  about  50  car- 
tilage rings  and  lined  with  mucous  membranes.  It  begins  at 
the  cricoid  cartilage  above  and  terminates  in  the  bronchi  below. 
It  therefore  connects  the  larynx  and  bronchi.  It  is  lined  by  a 
mucous  membrane  which  is  covered  by  ciliated  cells. 

Bronchi. — The  bronchi  are  two  in  number,  are  branches  of  the 
trachea,  and  very  similar  to  it  in  structure  and  function.  One 
bronchus  attaches  to  the  root  of  each  lung. 

Each  bronchus  divides  into  smaller  and  smaller' branches  like 
the  branches  of  a  tree.  At  the  end  of  each  terminal  branchiole 
there  is  a  minute  cavity,  the  air  sac  or  alveolus,  and  making  up 
the  wall  of  this  alveolus  are  a  large  number  of  microscopic  air 


RESPIRATION  55 

cells.  Microscopic  blood  vessels  are  placed  everywhere  between 
alveoli  and  in  their  walls.  Thus,  we  have  in  effect  a  thin  sheet 
of  blood  separated  from  a  thin  sheet  of  air  by  the  thinnest  pos- 
sible layer  of  animal  membrane. 

Lungs. — There  are  two,  right  and  left.  These  are  the  essential 
organs  of  respiration,  and  are  located  in  the  thoracic  cavity. 
The  pleura  is  a  thin  serous  membrane  one  layer  of  which  lines 
the  chest  cavity.  Another  layer  encloses  the  lungs,  each  in  a 
separate  sack.  Each  lung  is  cone-shaped.  In  the  lungs  of  a 
horse  the  lobes  are  not  distinctly  marked.  Some  authors  make 
no  definite  divisions;  others  describe  the  right  lung  as  having 
three  lobes,  and  the  left  tw^o. 

In  the  cow's  lungs  the  lobes  are  distinctly  marked.  The  left 
lung  has  three  distinct  lobes.  The  right  lung  has  four  lobes 
by  reason  of  the  anterior  lobe  being  divided  into  two  parts :  first 
and  second. 

The  bronchi  are  subdivided  until  they  are  very  small  and  are 
then  called  bronchioles.  Each  bronchiole  terminates  in  a  very 
small  cavity  made  by  a  number  of  air  cells  opening  together. 
These  cells  have  very  thin  walls,  and  are  separated  by  loose  con- 
nective tissue  in  which  minute  blood  vessels  are  located.  Blood 
is  then  separated  from  the  air  by  only  a  very  thin  membrane. 

Practical  application. — The  agricultural  student  who  takes 
"Dressing  and  Curing  Meats"  should  make  observations  con- 
cerning the  probable  relations  between  external  appearance  of 
the  chest  and  actual  chest  capacity.  This  question  has  fre- 
quently arisen  in  connection  with  discussions  on  bovine  tuber- 
culosis. Is  the  external  appearance  probably  a  reliable  guide  as 
to  actual  chest  capacity?    Why  or  why  not? 

Study  a  skeleton  or  chart  and  note  the  curvature  of  the  ril)s. 
Bear  in  mind  that  the  ribs  move  forward  and  outward  during 
inspiration.  What  relation,  if  any,  between  length  of  rib,  de- 
gree of  rib  curvature  and  possil)le  chest  expansion?  What  type 
of  nostril,  nasal  chamber,  and  larynx  do  you  usually  find  with 
great  lung  capacity? 

The  working  efficiency  of  every  cell  in  the  body,  nerve,  muscle, 
secretory  gland  cell  {e.g.,  milk  gland),  depends  greatly  upon  its 
supply  of  oxygen  and  the  removal  of  its  waste. 

Disorders  of  the  respiratory  organs  are  many  and  usually  re- 
quire professional  treatment.  The  following  are  practical  ex- 
amples of  respiratory  disorders:  Catarrh  of  respiratory  mucous 


56  VETERINARY  STUDIES 

membrane   may   affect   any    portion   of   it.     This   is  expressed 
by  irritation,  inflammation,  and  discharge. 

Bronchitis  is  an  inflammation  of  the  mucous  membrane  lining 
the  bronchial  tubes.  This  may  be  acute  and  severe  or  chronic 
and  mild.  Its  characteristics  are  local  irritation,  chill,  fever, 
cough  and  discharge,  with  increased  pulse  and  hurried  respira- 
tion, especially  the  cough. 

Pneumonia  is  an  inflammation  of  the  lung  substance,  i.e.,  air 
sacs  or  alveoli,  air  cells  and  other  tissues  of  the  lungs.  Here 
we  have  chill,  fever,  great  depression,  respiration  hurried  and 
out  of  the  usual  ratio  of  about  1 :  4  with  the  pulse,  increased 
pulse,  dark  mucous  membranes  and  marked  fever,  especially 
the  depression,  greatly  hurried  respiration,  and  dark  mucous 
membranes,  e.g.,  that  of  the  eye. 

Congestion  of  the  lungs  is  merely  an  over  filling  of  the  blood 
vessels  of  the  lungs  to  an  extent  that  interferes  with  capacity 
and  movement  of  air  in  the  alveoli  and  air  cells.  The  symptoms 
are  those  of  suffocation,  extremely  short,  hurried  respiration  and 
dark  mucous  membranes. 

Pleurisy  is  an  inflammation  of  the  pleura  and  is  local  or  gen- 
eral. Its  chief  expression  is  extreme  pain  on  movement  of  the 
affected  portion  of  the  pleura  as  in  breathing,  coughing  or  any 
movement  of  the  body  that  affects  the  inflamed  pleura.  Other 
symptoms  noted  by  the  veterinarian  are  e.g.,  fever,  fluid  in  the 
pleural  (chest)  cavity,  friction  sound,  peculiar  way  of  breath- 
ing, etc. 

Tuberculosis  often  affects  the  lungs  especially  in  cattle.  This 
is  characterized  by  enlarged,  cheesy  and  gritty  abscess  pockets 
in  the  lung  substance  and  glands  of  the  thoracic  cavity. 

Roaring  is  a  disease  of  the  larynx.  In  this  one  of  the  aryte- 
noid cartilages  is  paralyzed,  falls  in  the  way  of  the  air  current 
during  inspiration  and  causes  a  noisy  inspiration  called  roaring 
when  the  horse  is  exerted. 

Heaves  is  another  respiratory  disorder,  characterized  by  a 
harsh  cough  and  difficult  expiration.     (See  Lect.  XLVII.) 


LECTURE  XI 
DIGESTIVE  APPARATUS 

Definition. — The  digestive  apparatus  consists  of  various  or- 
gans Avhich  carry  on  the  processes  of  food  reception,  digestion, 
and  absorption.  The  digestive  apparatus  also  expels  various 
undigested  and  waste  materials.  The  organs  of  digestion  are 
the  mouth,  pharynx,  esophagus,  stomach,  and  intestines,  together 
■with  certain  other  organs ;  viz.,  the  salivary  glands  at  the  mouth, 
and  tlie  liver  and  pancreas  in  the  abdominal  cavity. 

Mouth. — At  the  mouth  we  find  the  lips,  teeth,  tongue,  and 
palate. 

The  horse  has  a  freely  movable  and  sensitive  upper  lip,  which 
is  used  in  selecting  food.  Tlie  cow  has  hard  cartilaginous  lips 
and  selects  her  food  mainly  by  the  tongue. 

The  tongue  is  used  by  the  cow  to  select  and  gather  her  food, 
and  by  all  animals  to  control  the  food  while  in  the  mouth  and 
assist  in  swallowing.  This  organ  is  composed  largely  of  muscu- 
lar tissue  with  some  connective  tissue,  and  is  covered  by  the 
common  mucous  membrane.  Its  surface  is  studded  with  several 
kinds  of  papillae,  similar  to  those  on  the  human  tongue.  These 
aid  in  controlling  the  food  while  in  the  mouth  and  have  to  do 
with  the  sense  of  taste.  They  are  especially  prominent  and 
strong  on  the  cow's  tongue. 

The  hard  palate  forms  the  roof  of  the  mouth,  and  consists  of 
portions  of  the  superior  maxillary  and  palate  bones  covered  by 
tough  connective  tissue,  and  overlaid  with  mucous  membrane. 
This  connective  tissue  and  its  covering  of  mucous  membrane  is 
thrown  up  into  a  series  of  transverse  ridges,  easily  seen  on  the 
roof  of  a  horse's  mouth,  sometimes  called  "bars." 

The  soft  palate  is  a  membranous  structure  containing  some 
musciil;ii-  tissue.  Its  function  is  to  separate  the  posterior  open- 
ing of  the  nose  chamber  and  pharynx  from  the  mouth. 

The  principal  salivary  glands  on  each  side  are:  one  parotid, 
one  submaxillary,  and  one  sublingiuil.  They  secrete  saliva  which 
helps  to  change  insoluble  and  useless  starch  into  a  soluble  and 

57 


58 


VETERINARY  STUDIES 


useful  sugar.  It  also  assists  in  swallowing  by  so  moistening  the 
food  that  it  passes  easily  along.  This  is  especially  important 
for  animals,  especially  the  ruminants,  like  the  horse,  cow,  and 
sheep,  that  live  upon  a  dry  and  more  or  less  bulky  food  and 
require  very  large  quantities  of  saliva. 

The  jiofotid  is  located  behind  the  lower  jaw  and  below  the 
base  of  the  ear.  It  is  connected  with  the  mouth  by  Steno's  duct, 
through  which  its  saliva  flows  to  the  mouth. 

The  suhmaxiUary  lies  in  the  space  between  the  flat  portions  of 
the  inferior  maxilla,  external  to  the  larynx.     Its  saliva  reaches 


Fig.  29. — Stomach  of  the  Horse. 

1.  External  View.    A,  esophagus;  B,  pyloric  portion;  C,  duodenum;  E,  E, 
left  sac;  F,  right  sac. 

2.  Internal  View.     B,  right  sac;   C,  duodenum;   E,  esophagus. 


the  mouth  through  AVharton's  duct,  which  opens  at  the  side  of 
that  portion  of  the  tongue  where  it  attaches  underneath. 

The  suhlingiial  lies  beneath  the  tongue,  and  its  saliva  escapes 
into  the  mouth  through  fifteen  or  twenty  small  ducts,  the  ducts 
of  Rivini.  The  work  of  each  organ  and  each  step  in  digestion 
depends  to  a  great  extent  upon  the  normal  condition  and  work 
of  the  preceding. 

Pharynx. — The  pharynx  belongs  to  both  the  digestive  and 
respiratory  systems  and  was  described  in  the  lecture  on  respi- 
ration. 

Esophagus. — The  esophagus  is  a  slender,  elastic  tube  four  to 
five  feet  long  and  one  inch  in  diameter,  connecting  the  pharynx 
and  stomach.  It  is  composed  of  two  coats  or  layers.  The  inner 
is  mucous  membrane ;  the  outer  is  muscular,  and  is  composed  of 


DIGESTIVE  APPARATUS 


59 


two  sets  of  muscle  fibers,  one  set  encircling  the  esophagus,  the 
other  placed  lengthwise. 

In  cattle  and  sheep,  the  esophagus  terminates  at  the  opening 
between  the  first  and  second  stomachs  in  the  trough-like  "esopha- 
geal groove."  This  groove  is  about  six  inches  long  and  connects 
with  the  first,  second  and  third  stomachs.  It  controls  the  move- 
ment of  food  and  water  to  the  several  stomachs.  When  food  is 
first  swallowed,  it  passes  mainly  into  the  cow's  first  stomach 
although  some  of  it  usually  goes  to  the  second.    Liquids,  includ- 


FiG.  30. — Stomach  of  the  Cow. 

A,  A,  and  B,  B,  different  portions  of  the  paunch  or  rumen;  C,  termina- 
tion of  the  esophagus;  D,  second  stomach  (reticuhim)  ;  E,  third  stomach 
(omasum)  ;  F,  F,  fourth  stomach  (abomasum)  ;  G,  small  intestine,  just 
beyond  the  pylorus;  II,  esophagus. 


ing  soluble  foods,  pass  on  to  the  second  and  third,  the  overflow 
even  })assing  into  the  fourth. 

Stomach. — The  stomach  is  located  in  the  anterior  portion  of 
the  abdominal  cavity.  Its  function  is  to  receive  food  and 
furnish  the  gastric  juice  to  aid  in  digestion. 

The  horse's  stomach  shows  two  distinct  portions.  The  mu- 
cous membrane  which  lines  the  interior  on  the  left  side  is  light 
colored,  firm,  and  tough,  like  the  mucous  membrane  of  the 
esophagus,  of  which  it  is  a  continuation.  On  the  right  side  of 
the  stomach  the  mucous  membrane  is  soft  and  red.  Thus  the 
horse  has  a  partially  double  or  two-ca^^ty  stomach  as  compared 
with  the  four-cavity  stomach  of  the  cow  and  the  sheep.     The 


60  VETERINARY  STUDIES 

horse's  stomach  hokis  about  31/2  gallons,  and  the  cow's  stomachs 
about  45  gallons.  The  cow's  stomach  is  compound  with  four 
cavities. 

The  first  cavity,  the  paunch  or  rumen,  is  much  the  largest,  and 
acts  as  a  sort  of  storage  vat  where  a  certain  amount  of  fermenta- 
tion occurs,  probably  as  a  process  of  digestion.  It  holds  about 
36  gallons  and  is  partly  divided  into  two  sacs,  right  and  left. 
Its  lining  mucous  membrane  is  more  or  less  covered  with  a 
coarse  moss-like  mass  of  papillaj. 

The  second  cavity,  the  reticulum  (tripe),  is  smaller  than  the 
first  and  connects  freely  with  the  rumen  and  with  the  third 
cavity.  Its  mucous  lining  is  built  into  a  coarse,  heayj^,  honey- 
comb-like structure  commonly  called  tripe.  Its  function  is  ap- 
parently storage,  particularly  of  water,  thereby  aiding  the  ru- 
men in  its  work  of  rumination  by  holding  a  needed  reserve 
supply  of  water.    Its  capacity  is  about  2.5  gallons. 

The  third  cavity,  the  omasum  (manyplies),  holds  about  3  gal- 
lons and  its  interior  is  almost  filled  with  a  mass  of  flat,  leaf-like 
folds  of  the  mucous  membrane.  The  surface  of  these  folds  is 
covered  with  small,  hard  papillie,  which  are  believed  to  complete 
the  work  of  the  teeth  by  further  reducing  the  food  particles. 
The  thin  cakes  of  food  between  the  folds  are  normally  rather 
dry. 

The  fourth  stomach,  abomasium,  is  the  true  stomach.  Its  lin- 
ing is  a  soft,  pink  mucous  membrane  containing  the  gastric 
glands,  which  produce  the  gastric  juice  for  the  work  of  diges- 
tion. Anatomically,  the  first  three  cavities  or  stomachs  are 
really  bulges  in  the  esophagus.  The  abomasum  receives  food 
and  water  from  the  omasum  and  discharges  them  into  the  first 
section  of  the  small  intestine.  Its  digestive  fluid  (gastric  juice) 
is  largely  water,  and  contains  pepsin,  hydrochloric  acid,  and 
rennin  ferment,  and  aids  in  digestion  of  proteid  food  materials. 

Gastric  juice  is  furnished  by  glands  in  the  right  side  of  the 
horse's  stomach,  and  by  the  cow's  fourth  stomach.  The  effect 
of  gastric  juice  is  to  make  proteid  matters  soluble.  It  does  this 
by  the  action  of  its  pepsin  ferment,  which  is  very  active. 

Small  intestine. — This  begins  at  the  stomach,  the  common 
opening  being  guarded  by  the  pylon^s,  a  strong  spliincter  muscle 
like  a  purse  string.  The  small  intestine  is  divided  into  three 
parts:  duodenum,  jejunum,  and  ileum.  The  small  intestine  is 
about  72  feet  long  in  the  horse  and  140  feet  long  in  the  cow,  and 


DIGESTIVE  APPARATUS  61 

extends  from  the  stomach  to  the  cecum,  at  which  point  the  large 
intestine  begins. 

The  stomach,  and  the  small  and  large  intestine  have  the  same 
three  coats :  inner  mucous,  middle  muscular,  and  outer  serous. 

The  mucous  coat  in  the  small  intestines  is  thickly  studded 
with  villi.  Various  intestinal  glands  furnish  fluids  which  assist 
in  digestion. 

The  muscular  coat  is  composed  of  two  sets  of  fibers;  those  of 
one  set  encircle  the  bowel,  and  those  of  the  other  set  run  length- 
wise. This  arrangement  is  for  the  purpose  of  producing  peri- 
staltic action  of  the  intestines,  i.e.,  the  writhing  movements 
seen  in  dissection  work  or  in  butchering  when  the  warm 
intestine  is  quickly  removed  and  exposed  to  the  air. 

The  outer  coat  is  the  peritoneum,  a  serous  membrane  which 
lines  the  abdominal  cavity  and  also  covers  the  various  abdomi- 
nal organs. 

The  liver  is  the  largest  gland  in  the  body,  weighing  about  11 
pounds,  and  is  situated  in  the  abdominal  cavity  on  the  right 
side  and  well  forward  against  the  diaphragm.  It  manufactures 
about  12  pounds  of  bile  in  24  hours.  The  liver  of  the  horse 
shows  three  fairly  distinct  lobes,  namely,  the  left,  right  and 
middle.  The  liver  is  inclosed  in  a  strong  capsule  called  Glis- 
son's  capsule.  The  cow  has  a  gall  bladder  but  the  horse  has 
none,  and  from  the  horse's  liver,  bile  flows  more  or  less  con- 
stantly into  the  intestine.  Bile  aids  somewhat  in  digestion  of 
fats ;  it  has  a  slight  cathartic  effect ;  it  aids  absorption  and  tends 
to  prevent  putrefaction.  The  liver  cells  convert  sugar  received 
from  the  blood  into  animal  starch  (glycogen),  and  store  it  up 
as  such,  and  finally  they  reconvert  this  glycogen  into  a  soluble 
sugar  and  give  it  out  to  the  blood  in  proportion  as  the  blood 
loses  its  sugar.  One  of  the  most  important  functions  of  the  liver 
is  to  remove  or  else  make  harmless,  various  poisons  which  origi- 
nate in  the  body  and  are  taken  to  the  liver  by  the  blood.  Also 
the  bile  aids  the  pancreatic  enzymes. 

Pancreas. — The  pancreas  is  much  smaller  than  the  liver,  weigh- 
ing only  about  17  ounces,  but  is  said  to  furnish  about  11  pounds 
of  pancreatic  fluid  daily.  It  is  located  in  the  abdominal  cavity 
below  the  posterior  aorta  and  behind  the  stomach  and  liver. 
The  ends  are  called  head  and  tail ;  it  is  long,  ti-iangular  and 
much  like  a  big  salivary  gland.  Pancreatic  fluid  empties  into 
the  intestine  at  or  near  the  bile  duct.     This  fluid  contains  four 


62  VETERINARY  STUDIES 

different  ferments;  one  which  acts  on  starch,  a  second  on  pro- 
tein, another  on  fats,  and  one  Avhich  curdles  milk.  Pancreatic 
juice  is  probably  the  most  important  of  the  digestive  fluids. 

Large  intestine. — In  the  horse  this  is  about  25  feet  long,  with 
a  capacity  of  33  gallons ;  in  the  cow,  42  feet  long  with  a  capacity 
of  18  gallons.  Its  parts  include  the  cecum,  large  colon,  small 
colon. 

The  cecum  (blind  pouch)  of  the  horse  is  three  and  a  half  feet 
long  with  a  capacity  of  71/2  gallons.  The  cecum  of  the  cow  is 
much  smaller,  being  about  30  inches  long  and  5  inches  in  diam- 
eter. Its  inlet  from  the  small  intestine  and  the  outlet  to  the 
large  colon  are  at  one  end  of  the  cecum ;  the  other  end  forms  a 
blind  pouch. 

The  equine  cecum  appears  to  serve  about  the  same  function 
as  the  bovine  rumen,  i.e.,  holding  for  maceration  and  fermenta- 
tion, which  facilitates  the  digestion  of  crude  fiber. 

The  large  colon  of  the  horse  is  12  feet  long  with  a  capacity  of 
20  gallons.  Here  is  where  most  of  the  gas  collects  when  a  horse 
bloats  in  a  case  of  flatulent  colic. 

The  simall  colon  in  the  horse  is  10  feet  long,  capacity  6  gal- 
lons. In  a  cow  the  large  and  small  colons  are  studied  together, 
and  are  35  feet  long,  with  a  capacity  of  14  gallons. 

The  large  intestine  of  both  animals  is  long,  large,  and  saccu- 
lated to  hold  contents  a  long  time  and  offer  a  large  amount  of 
absorbing  surface.  It  takes  contents  about  five  days  to  pass 
through  the  alimentary  tract  of  the  cow,  and  about  three  days  to 
pass  through  that  of  the  horse. 

Practical  application. — At  this  point  the  student  may  have  a 
practical  and  interesting  exercise  by  dissecting  out  the  gullet, 
stomach  and  intestine,  liver  and  pancreas  of  one  or  more  domes- 
tic animals.  Sheep  and  hogs  are  convenient  to  handle  and  very 
satisfactory  if  one  or  two  animals  can  be  used.  This  work  may 
be  taken  up  in  connection  with  classes  in  "dressing  and  curing 
meats"  or  in  the  dissection  room.  The  student  should  actually 
see  and  handle  these  organs  if  possible.  He  should  endeavor  to 
see  the  mouth,  not  in  a  vague  way,  but  as  a  place  where  a  horse 
may  have  diseased  teeth  and  toothache,  or  have  a  very  sore 
mouth,  caused  by  the  beards  of  wild  barley,  or  squirrel  tail 
grass;  and  as  a  place  where  young  pigs  may  have  canker  sore 
mouths. 

He  should  see  the  esophagus  as  a  tube  much  like  a  piece  of 


DIGESTIVE  APPARATUS  63 

rubber  tubing,  except  that  the  esophagus  is  composed  of  mus- 
cular tissue  lined  with  mucous  membrane.  He  should  also  see 
it  as  a  tube  that  is  liable  to  choke  on  dry  oats  or  a  piece  of 
potato.  The  stomach  should  be  seen  as  a  hollow  organ  that  may 
become  inflamed  or  filled  with  a  mass  of  rapidly  fermenting 
food  in  a  case  of  bloat.  The  intestine  should  be  seen  as  a  long, 
soft  tube,  built  up  of  the  same  three  layers  as  the  stomach,  but 
very  long,  much  folded,  and  delicate  of  structure  and  as  an 
organ  in  which  may  occur  an  inflammation  (enteritis)  or  an 
impaction  of  dry  contents  and  stoppage.  The  whole  intestine 
should  be  regarded  as  a  very  long  tube  lined  with  a  sheet  of 
mucous  membrane  for  the  production  of  digestive  fluids  and 
for  the  absorption  of  nutrients. 

Diseases  of  the  digestive  organs  are  numerous.  Many  are  pre- 
ventable. Some  of  these  diseases  are  easily  recognized  and,  in 
the  absence  of  veterinary  help,  may  be  fairly  well  treated  by 
the  stockman,  e.g.,  bloat  in  cattle  and  sheep  and  canker  sore 
mouth  in  young  pigs.     See  later  chapters. 


LECTURE  XII 
PHYSIOLOGY  OF  DIGESTION 

Definition, — Digestion  is  a  chemical  and  physical  process  by 
which  food  matters  are  made  soluble  and  capable  of  absorption. 

The  digestive  fluids  are  saliva,  gastric  juice,  pancreatic  juice, 
bile  and  intestinal  juice.  These  are  the  active  agents  which 
bring  about  the  changes  necessary  to  render  food  matters  soluble 
and  absorbable. 

Food  groups. — These  are  of  two  general  classes:  organic  and 
inorganic. 

The  organic  group  is  divided  into  three  subgroups:  carbohy- 
drates (sugars  and  starches)  ;  proteids  (egg  albumin,  casein, 
gluten,  etc.)  ;  and  fats. 

The  inorganic  group  includes  water,  sodium,  potassium,  lime, 
sulphur,  phosphorus,  iron,  etc.  These  form  a  very  important 
part  of  the  ration.  Normal  growth  of  young  animals  is  impos- 
sible without  the  necessary  mineral  matters,  especially  phos- 
phate of  lime,  which  forms  about  four  fifths  of  the  total.  In 
case  of  older  animals  a  mineral-deficient  diet  results  in  a  mineral 
drain  from  the  tissues,  for  example  in  case  of  a  cow  giving  milk 
or  carrying  a  calf. 

Course  and  History  of  Food  Groups 

Carbohydrates. — Starch  cells  are  broken  up  by  the  teeth,  and 
the  starch  is  changed  by  the  saliva  ^  and  pancreatic  juice  into 
soluble  sugars.  Physiologists  differ  somewhat  as  to  details,  but 
during  the  process  of  digestion  at  least  two  sugars, — dextrose 
(grape  sugar),  maltose  and  dextrine,  an  intermediate  body  be- 
tween sugar  and  starch,  are  formed.  After  these  chemical 
changes  come  absorption,  storage  in  the  liver,  then  distribution, 
and  use.    A  large  part  of  the  products  are  taken  into  the  portal 

'■  Authorities  differ.  Some  deny  the  power  of  herbivorous  saliva  to  do 
this. 

64 


PHYSIOLOGY  OF  DIGESTION  65 

circulation  and  carried  to  the  liver.  Most  of  the  portion  carried 
to  the  liver  is  there  changed  back  from  sugar  to  a  starch  called 
glycogen  and  stored  in  the  liver  as  such.  As  the  blood  loses  its 
sugar,  it  is  resupplied  from  the  liver.  Thus  the  liver  becomes 
a  storehouse  for  surplus  sugar  and  at  the  same  time  serves  to 
maintain  a  uniform  percentage  of  sugar  in  the  blood.  Some 
of  tiie  sugar  may  be  changed  into  fat.  The  fat  and  sugar  are 
ultimately  oxidized,  liberating  mechanical  energy,  heat,  CO2, 
and  water.  The  two  latter  are  excreted  by  the  skin,  lungs  and 
kidneys. 

Proteids. — These  are  not  affected  by  the  saliva.  But  they  are 
changed  to  soluble  amino  acids,  intermediate  products,  and 
blood  proteids  by  the  gastric  and  pancreatic  juices,  and  by  the 
epithelial  cells  which  line  the  intestine  and  through  which  ab- 
sori)tion  takes  place.  The  digested  proteids  are  then  absorbed 
into  the  blood  which  goes  to  the  liver,  and  are  ultimately  dis- 
tril)uted  to  tissue  cells  to  replace  worn  out  parts  or  to  build  up 
new  parts  as  in  growing  animals. 

It  has  been  held  that  proteid  nutrients  are  especially  neces- 
sary to  repair  tissues  that  have  been  worn  out  by  mechanical 
work;  but  there  is  good  reason  to  suppose  that  this  has  been 
overestimated  in  the  past,  and  that  carbohydrates  have  much  to 
do  with  the  ultimate  source  of  physical  power. 

The  proteid  products  are  finally  oxidized,  and  give  heat  and 
mechanical  energy.  They  are  excreted  from  the  body  as  CO2, 
urea  and  water.  The  urea  is  excreted  mainly  by  the  kidneys, 
and  the  water  by  all  the  excretory  organs. 

Fats. — These  are  digested  mainly  by  the  pancreatic  fluid. 
They  are  not  acted  on  by  either  the  saliva,  or  the  gastric  juice, 
and  they  are  but  slightly  affected  by  the  bile,  although  the 
latter  is  indirectly  important  in  the  digestion  and  absorption 
of  fats.  The  pancreatic  fluid  emulsifies  a  portion  which  reaches 
the  laeteals  in  this  emulsified  condition.  The  remainder  is  di- 
gested by  separating  the  glycerin  from  the  fatty  acid  (fat  con- 
sists of  a  fatty  acid  plus  glycerin).  Glycerin  is  readily  soluble 
and  easily  absorbed.  The  fatty  acid  unites  with  alkaline  ma- 
terial from  the  bile  and  pancreas  to  form  soluble  soap,  and  thus 
the  remainder  of  the  fat  is  absorbed.  Distribution  is  made 
by  the  blood  current  and  finally,  assimilation  takes  place, 
i.e.,  building  tissue  cells,  and  then  oxidation.  Fat  may 
either  be  deposited  into  and  become  a  part  of  tlie  cell  bodies 


66  VETERINARY  STUDIES 

or  it  may  be  deposited  between  the  cells,  where  it  becomes  a 
stored  reserve.  Under  some  conditions  such  storing  np  of  fatty 
matter  may  constitute  a  diseased  condition,  as  when  the  heart 
muscle  undergoes  fatty  degeneration.  The  final  changes  which 
fats  undergo  are  oxidation,  whereby  heat  and  mechanical  energy 
are  given  out,  and  then  excretion  as  CO2  and  water. 

Practical  application  and  suggestions. — INIature  animals  need 
a  constant  supply  of  food  to  provide  heat  and  energy  for  physi- 
cal work  and,  in  the  case  of  fattening  animals,  to  furnish  stor- 
age fat.  Young  and  growing  animals  must  have  food  to  supply 
heat  and  energy  for  physical  work,  and  also  for  the  building  of 
new  cells. 

The  more  thorough  the  digestion  and  absorption,  the  better 
will  be  returns  for  food  consumed,  although  large  gains  in 
weight  or  large  milk  production  do  not  seem  to  depend  so  much 
on  actual  difference  in  ability  to  digest  quantity  as  upon  ability 
to  assimilate  and  use  for  the  special  purpose. 

Thorough  digestion  with  imperfect  absorption  means  wasted 
food,  and  useless  work  for  the  digestive  organs. 

Generous  feeding  is  therefore  not  enough;  there  must  be  in- 
telligent feeding. 

Best  results  are  secured  when  feeding  is  regular  and  when 
the  rations  are  well  balanced  and  the  bowels  are  in  a  condition 
midway  between  diarrhea  and  constipation. 

Both  digestion  and  absorption  depend  to  a  considerable  extent 
upon  the  condition  of  the  mucous  membrane  lining  the  digestive 
tube,  through  which  absorption  must  take  place.  To  get  the 
best  results  from  food,  with  the  least  risk  to  health,  horses 
should  receive  most  of  their  water  before  feeding. 

Usually  there  is  no  profit  in  grinding  grain  for  horses,  unless 
they  have  poor  teeth  or  eat  too  rapidly ;  and  yet  this  may  be 
economical  when  done  on  a  large  scale.  This  method  is  to  cut 
and  wet  the  hay  or  straw,  then  mix  in  the  ground  grain.  This 
is  a  safe  method  and  secures  thorough  digestion  and  absorption, 
and  horses  so  fed  are  not  stuffed  wdth  hay. 

Only  as  much  hay  should  be  fed  at  one  time  as  the  horse  will 
clean  up  at  each  feed  with  the  grain.  Feeders  are  usually  sur- 
prised to  find  how  well  their  horses  do  with  greatly  reduced  hay 
ration  and  the  same  amount  of  grain.  There  is  less  danger 
from  stomach  and  bowel  troubles,  and  almost  no  danger  from 
heaves. 


PHYSIOLOGY  OF  DIGESTION  07 

Dry  bran  for  horses  that  eat  hurriedly  is  to  be  avoided  as 
such  horses  are  liable  to  choke  on  it. 

The  cow's  stomach  is  quite  different  from  that  of  the  horse  in 
its  plan  and  size,  and  her  intestinal  canal  is  nearly  twice  as 
long.  Her  large  paunch  and  other  stomachs,  as  well  as  the  long 
intestine,  indicate  that  she  can  utilize  a  coarser  diet  than  the 
horse,  and  that  she  can  digest  and  absorb  such  foods  more  thor- 
oughly. They  also  indicate  that  nature  intends  her  to  eat  larger 
quantities  at  a  time  and  at  longer  intervals  than  the  horse,  and 
that  the  same  is  true  as  to  the  amount  of  water  she  drinks. 

Idle  horses  are  frequently  overfed.  This  is  not  only  a  waste 
of  food  but  an  actual  injury  to  the  horse,  and  creates  a  ten- 
dency to  such  diseases  as  azoturia,  lymphangitis  (elephant  leg), 
and  heaves. 

Horses  doing  ordinary  work  need  from  30  to  50  per  cent 
more  grain  with  the  same  roughage  as  compared  with  idle 
horses.  Horses  on  winter  pasture,  cornfields,  etc.,  need  from 
one  third  to  one  fourth  as  much  grain  as  when  at  moderate  work. 
The  horse  that  is  off  work  should  have  exercise  every  day  if 
possible.  Exercise  lessens  very  much  the  danger  from  many 
diseases. 


LECTURE  XIII 
URINARY  ORGANS 


The  urinary  organs  are  the  kidneys,  ureters,  bladder,  and 
urethra. 

Kidneys. — These  two  important  organs  are  situated  in  the 
sublumbar  regions  and  are  supported  in  place  by  large  blood 
vessels  and  connective  tissue.  They  differ  in  shape,  size,  and 
location,  the  right  kidney  being  larger,  farther  forward,  and 
more  nearly  round  than  the  left.     Each  is  covered  by  a  fibrous 

capsule  from  which 
bundles  of  connect- 
ive tissue  branch  to 
penetrate  the  organ 
and  form  a  frame- 
work. 

Internal  struc- 
ture. The  kidneys 
have  a  rich  blood 
supply  from  the 
renal  arteries,  which 
branch  directly 
from  the  posterior 
aorta.  One  set  of 
capillaries  supplies 
the  M  a  1  p  h  i  g  i  a  n 
body,  the  other  supplies  the  tubules.  A  kidney  is  essentially 
a  mass  of  minute  tubes  held  together  by  connective  tissue,  and 
supplied  with  a  large  quantity  of  blood.  On  cutting  open  a 
kidney  we  may  see  two  distinct  portions  separated  by  a  wavy 
line,  and  a  cavity  at  the  root.  The  two  portions  are  the  cortical 
(outside)  and  the  medullary  (center). 

The  cavity  at  the  root,  called  the  pelvis,  is  merely  the  funnel- 
shaped  origin  of  the  ureter. 

Urine  tubules  make  up  a  large  part  of  the  bulk  of  the  kidney. 
Each  tubule  begins  in  the  cortical  portion,  in  a  little  sac  like 

68 


Fig.  31.- 


-Lengthwise  Section  of  the  Horse  's 
Kidney. 


a,  cortical  portion;  b,  medullary  portion;  d,  d, 
d,  pelvis;  g,  ureter. 


URINARY  ORGANS 


69 


cavity,  the  Malphigian  body  within  which  is  a  tangled  network 
of  finest  arterioles,  the  glomerulus.  The  little  sac  narrows  at 
the  open  end,  and  from  this  narrowed  neck  continue  the  tubule. 
Each  tubule  makes  certain  convolutions,  descends  to  the  medul- 
lary portion,  and  thence  returns  to  the  cortical,  where  it  makes 

other    convolutions ;    fi- 

RA. 

\ 


L.  KIDNEY 


KIDNEY 


URETER 


URETER 


nally  terminating  in  a 
larger  duct  through 
which  the  urine  escapes 
to  the  pelvis  of  the  kid- 
ney and  then  into  the 
ureter.  Each  tubule  is 
thus  very  long  in  pro- 
portion to  its  size,  and 
there  are  a  large  number 
of  them. 

Function  of  the  kid- 
neys.— The  kidneys  have 
four  functions:  {a)  to 
remove  useless  or  waste 
and  poisonous  materials 
from  the  blood  ;  ( & )  to 
remove  excess  of  normal 
substances  from  the 
blood;  (c)  to  keep  the 
blood  faintly  alkaline 
by  removing  or  adding 
alkaline  materials  as 
needed;  {dk)  to  main- 
tain normal  volume  and 
concentration  of  the 
blood. 

How  accomplished. — 
The  water  and  salts  in 

solution  are  removed  from  the  blood  within  the  little  sacs  at  the 
beginnings  of  the  tubules.  This  probal)ly  is  done  by  a  process  of 
filtration  under  pressure.  The  urea,  albumin,  etc.,  are  dis- 
charged farther  on  into  the  water  of  the  urine  tubules.  These 
are  taken  from  the  blood  in  a  process  of  secretion  by  the  epi- 
thelial cells  which  line  the  tubules. 

Urine. — Urine  is  composed  of  water,  salts  of  sodium,  potas- 


FiG.  32. — Urinary  Apparatus  in  Diagram. 
{M.  n.  B.) 

P,  A,  posterior  aorta;  D,  D,  renal  arteries; 
P,  peritoneal  coat  of  bladder;  Mus.,  muscu- 
lar coat;  Muc,  mucous  coat. 


70  VETERINARY  STUDIES 

sium,  calcium,  etc.,  together  with  various  organic  matters,  as 
urea  and  uric  acid,  and  various  aromatic  substances  which  give 
the  odor.  Its  reaction  in  herbivorous  animals  is  alkaline.  The 
specific  gravity  for  horse's  urine  is  about  1036,  and  for  cow 
1025.  Either  may  vary  within  the  normal  range.  Horses  ex- 
crete about  10  pints  in  24  hours,  and  cattle  about  25  pints.  The 
urine  is  continuously  excreted  by  the  kidneys  and  runs,  drop 
by  drop  into  the  bladder. 

Ureters. — These  are  two  slender  tubes  which  conduct  urine 
from  the  kidneys  to  the  bladder.  They  are  about  the  size  of  a 
goose  quill,  about  one  foot  long,  and  they  terminate  at  the  blad- 
der, where  they  extend  for  an  inch,  between  its  muscular  and 
mucous  coats,  before  reaching  the  interior,  preventing  backward 
flow  of  urine  into  the  ureters. 

Bladder. — The  bladder  is  a  muscular  sac,  a  urine  reservoir, 
ovoid  in  shape,  located  in  the  inferior  and  anterior  part  of  the 
pelvic  cavity.  This  organ  is  supported  in  place  by  several  liga- 
ments, which  attach  to  neighboring  organs.  It  is  in  relation 
above,  in  the  male,  to  the  rectum ;  in  the  female,  to  the  uterus 
and  vagina  and  below  to  the  floor  of  the  pelvis.  It  is  covered 
in  front  by  peritoneum  and  is  in  relation  to  the  coiled  small 
intestine. 

Openings. — There  are  three  openings,  all  on  the  posterior  por- 
tion of  the  organ :  viz.,  one  leading  to  the  urethra,  and  two  for 
the  ureters.  The  neck  of  the  bladder  contains  circular  muscle 
fibers  which  act  as  a  sphincter  and  control  the  outlet  to  the 
urethra. 

Coats. — The  bladder  has  three  coats,  mucous,  muscular  (of 
several  layers),  and  serous  (peritoneal).  The  latter  covers  only 
a  portion  of  the  bladder. 

Urethra. — This  canal  conducts  urine  from  bladder  to  exterior 
of  body. 

Practical  application. — The  kidneys  should  be  seen  by  the 
student  as  a  device  for  bringing  a  constantly  renewed  and  thin 
sheet  of  blood  as  close  as  possible  to  a  thin  sheet  of  epithelial 
cells,  lining  a  suitable  device  (urine  tubules)  for  carrying  off 
the  product. 

The  ureters,  bladder,  and  urethra  should  be  seen  as  mechani- 
cal devices  for  disposing  of  the  urine. 

Disorders  of  the  urinary  organs  are  numerous,  but  not  of 
common  occurrence.    Diabetes  is  indicated  by  excessive  and  fre- 


URINARY  ORGANS  71 

quent  urination,  great  thirst,  loss  of  weight,  lack  of  endurance 
and  unthrift.  Treatment  depends  largely  on  removal  of  the 
cause,  often  bad  food  or  irritant  medicine.  Suppression  of 
urine  is  usually  the  result  of  obstruction  in  bladder  or  urethra, 
disease  of  kidneys,  paralysis  of  bladder  and  other  such  causes. 
It  is  a  symptom  rather  than  a  disease.  Uremia  or  poisoning  by 
unexcreted  products,  is  the  disease  which  results  from  sup- 
pression of  the  urine,  and  is  apt  to  be  serious. 

Azoturia  (see  Lecture  XLIV)  is  not  a  disease  of  the  urinary 
organs,  although  very  abnormal  urine  is  a  conspicuous  symptom. 

Nephritis  is  an  inflammation  of  one  or  both  kidneys  due  to 
irritant  food  or  medicine,  to  injury  from  calculus  (stone)  infec- 
tion, etc.  It  is  indicated  by  condition  of  the  urine — usually  less 
than  normal  and  rich  in  sediment — by  peculiar  attitude  and 
movement — especially  of  the  hind  parts — and  local  dropsy  of 
the  belly,  scrotum,  legs,  and  other  parts. 

Cystitis  is  an  inflammation  of  the  bladder  due  to  infection, 
injury,  calculus  or  irritant  medicines.  It  is  indicated  by  per- 
sistent, mild,  colicky  pains,  uneasy  movements  of  hind  feet,  and 
frequent  urination  with  persistent  pain  after  each  attempt. 
Urine  is  often  discharged  in  jets  instead  of  in  a  continuous 
stream.  Remove  the  cause  as  soon  as  possible  and  call  a  veteri- 
narian. 

Calculus  (stone)  in  the  bladder  occasionally  forms  as 
a  deposit  from  the  urine  and  causes  trouble.  Male  cattle  and 
sheep  that  have  been  overfed  on  roots  are  apt  to  form  small 
calculi  in  the  bladder  or  urethra.  Small  stones  may  escape  from 
the  bladder  and  obstruct  the  urethra.  Horses  are  liable  to  have 
larger  calculi  in  the  bladder.  The  s^nnptoms  then  are  those  of 
retention  of  urine  and  cystitis.  Examination  by  rectum  con- 
firms the  diagnosis.  Removal  may  be  made  by  veterinary 
operation. 


LECTURE  XIV 

MAMMARY  GLANDS 

The  cow's  udder  is  taken  as  a  type  of  mammary  gland.  It  is 
located  under  the  inguinal  region  and  supported  by  skin,  loose 
connective  tissue,  and  bands  of  white  fibrous  tissue  which  attach 
to  the  fibrous  tunic  of  the  abdomen  and  act  as  ligaments  to  help 
support  the  organ.  The  udder  is  covered  by  thin  soft  skin  and 
fine  hair. 

Anatomy. — The  udder  is  divided  into  two  lateral  halves,  each 
of  which  has  two  glands,  the  front  and  the  back.     Each  half  is 

incased  in  a  fibrous  sac  of  yellow  elas- 
tic tissue,  thus  the  two  lateral  halves 
are  well  separated  by  the  double,  con- 
nective tissue  membrane.  The  two 
quarters  in  each  half  are  not  so  sepa- 
rated. 

The    substance    of    each    gland    is 
Fig.  33.— One  Quarter  and     made  up  of  yellow  glandular  tissue, 
Teat  oF^Cmv  JUDDER.  connective   tissue,   nerves,  blood  ves- 

^      .„     .      "      TVT  ^  sels,  etc.     Each  gland  is  divided  into 

C,  milk  cistern.     Note  con-  '  ... 

striction    at    end    of    teat,     lobes,     which     are    subdivided     into 

Holes,  shown   in   the   gland      i^bules.      Each    quarter    of    a    cow's 
above,    are    milk    ducts    cut  .  i      i       i 

across.  •  udder  IS  merely  a  compound  gland, 

with  its  connective  tissue  framework, 
nerves,  blood  and  lymph  vessels,  etc.  The  gland  tissue  proper 
consists  of  a  mass  of  branching  tubes.  The  terminal  branches 
end  in  little  sac-like  cavities  called  alveoli.  These  and  the  milk 
ducts  (tubes)  are  lined  with  epithelial  cells  like  all  other  similar 
structures.  These  lining  cells  are  the  factories  in  which  the 
casein,  sugar,  fat,  etc.,  are  produced,  from  materials  brought  to 
them  by  the  blood  and  lymph. 

There  is  one  milk  duct  for  each  lobule.  These  small  ducts 
unite  to  form  larger  and  larger  ducts,  and  thus  the  milk  is  con- 
veyed into  the  milk  cistern  which  is  located  at  the  base  of  each 

72 


MAMMARY  GLANDS  73 

teat.  IMilk  escapes  from  the  cistern  through  a  single  large 
canal. 

The  milk  duct  is  closed  and  controlled  at  the  end  of  the  teat 
by  a  circular  involuntary  muscle  and  is  therefore  not  under  vol- 
untary control.  The  milk  ducts  draining  each  lobe  are  sur- 
rounded by  circular  voluntary  muscle  fibers  and  are  therefore 
under  voluntary  control.  By  these 
she  is  able  to  "hold  up"  her  milk. 

The  gland  structure  is  undevel- 
oped and  rudimentary  until  matur- 
ity is  reached,  and  does  not  become 
active  until  the  close  of  the  first 
pregnancy. 

The  growth  of  the  mammary  fig.  34.-Alveoli  and  Outlet 
gland   is   apparently   stimulated  by  Ducts.     Magnified. 

and  dependent  upon  some  substance 

given  to  the  blood  by  the  body  of  the  fetus  or  the  "yellow  body" 
of  the  ovary.  This  same  substance  appears  to  check  milk  secre- 
tion. Removal  of  the  body  of  the  fetus  by  birth,  or  absorption  of 
the  yellow  body  after  birth,  permits  the  glands  to  produce  milk. 

Blood  supply. — The  mammary  glands  receive  their  supply 
through  the  mammary  artery,  which  distributes  branches 
through  the  two  glands  in  each  half  of  the  udder,  one  mammary 
artery  on  each  side.  This  artery  divides  and  branches  until  the 
finest  arterioles  terminate  in  capillaries  distributing  blood  to 
every  portion  of  the  udder.  The  nutrition  for  one  half  of  the 
udder  thus  comes  through  the  external  iliac  artery,  then  through 
the  prepubic,  a  branch  of  the  external  iliac,  then  through  a 
branch  of  the  prepubic,  the  external  pudic.  The  mammary 
artery  is  one  of  the  terminal  branches  of  the  external  pudic. 
From  this  the  distribution  is  through  arterioles,  capillaries,  and 
lymph  spaces  to  the  cells. 

The  large  vein  which  may  be  felt  in  front  of  the  udder  on 
each  side,  and  called  by  dairymen  the  "milk  vein,"  is  properly 
the  subcutaneous  abdominal  vein.  Three  veins,  the  external 
pudic,  the  perineal  vein,  and  the  abdominal  subcutaneous  vein, 
drain  each  lateral  half  of  the  udder. 

Nerve  supply. — The  mammary  glands  have  their  nerve  supply 
through  the  first  lumbar  pair  of  spinal  nerves. 

Products. — Colostrum  is  the  fluid  which  accumulates  in  the 
udder  during  the  latter  part  of  pregnancy.    It  differs  from  milk 


74  VETERINARY  STUDIES 

in  that  it  contains  the  colostrum  cells,  a  few  oil  globules,  much 
albumin,  and  but  little  casein,  fat  or  sugar.  It  has  a  mild, 
cathartic  effect  on  the  young  animals. 

Milk  is  a  complex  alkaline  fluid  with  a  specific  gravity  of 
1018  to  1040.  It  is  composed  of  oil  globules  suspended  in  milk 
plasma,  and  is  therefore  an  emulsion.  Milk  globules  consist 
almost  entirely  of  fat.  They  are  from  .0004  to  .0012  of  an  inch 
in  diameter.  The  plasma  consists  of  water,  with  casein,  sugar, 
salt,  albumin,  and  whatever  else  may  be  in  solution  in  the  water. 

Milk  production. — The  production  of  the  casein,  sugar,  fat, 
etc.,  is  a  manufacturing  process,  not  mere  filtration;  for  there 
is  no  casein  or  milk  sugar  in  the  blood,  and  but  very  little  fat. 
Secreting  cells  take  certain  elements  from  the  blood  and  lymph 
and  put  them  together  to  make  the  milk  ingredients. 

The  formation  of  milk  consists  of  two  processes ;  one  of  these 
is  gland  secretion,  e.g.,  of  the  casein  and  milk  sugar,  by  the  lin- 
ing epithelial  cells.  In  the  other  process,  the  fat  or  cream  is 
formed  as  tiny  droplets  in  the  ends  of  these  cells.  The  end  of 
the  cell  may  either  cut  off  or  rupture,  freeing  the  fat  droplet  in 
the  cavity  of  the  alveolus.  The  cell  is  then  repaired  and  forms 
the  next  droplet,  of  fat. 

Practical  application. — It  is  important  to  remember  that  the 
two  lateral  halves  of  the  cow's  udder  are  completely  separated 
by  a  strong  partition,  but  that  the  front  and  back  quarters  in 
each  half  are  not  so  separated.  This  is  important  in  connection 
with  garget  and  other  diseases  of  the  udder. 

Pressure  of  milk  within  the  udder  checks  secretion;  removal 
of  this  pressure  stimulates  or  at  least  permits  secretion;  hence 
the  importance  of  complete  milking. 

The  quantity  and  quality  of  milk  depends,  first  of  all,  upon 
hereditary  peculiarities  of  the  individual  cow;  after  this  it  de- 
pends upon  food  and  thoroughness  of  digestion  and  absorption. 
They  depend,  also,  upon  the  length  of  time  the  cow  has  been 
milking,  the  length  of  time  she  has  been  carrying  her  calf,  the 
condition  of  her  nervous  system,  and,  to  a  very  great  extent, 
upon  the  quantity  and  composition  of  blood  passing  through  the 
udder. 

The  composition  of  blood  for  milk  production  depends  upon 
the  amount  and  character  of  food  received,  and  upon  the  thor- 
oughness of  digestion  and  absorption  from  intestines  into  the 
blood. 


MAMMARY  GLANDS  75 

The  relative  proportion  of  gland  tissue  and  connective  or 
framework  tissue  is  presumably  a  matter  of  heredity,  except  as 
the  udder  is  affected  by  injury  or  disease. 

Ability  to  digest  large  amounts  of  food  material,  the  tendency 
to  dairy  assimilation,  the  capacity  for  large  flow  of  blood  through 
the  udder,  the  tendency  to  a  large  number  of  gland  cells  within 
the  udder,  and  the  tendency  to  relatively  large  proportion  of 
gland  tissue  as  compared  with  the  connective  tissue  are  all  mat- 
ters of  heredity,  fixed  by  a  long  line  of  intelligent  breeding. 

Mare's  milk  differs  from  cow's  milk  in  possessing  more  water 
and  sugar  and  less  fat,  casein,  albumin,  and  mineral  matter. 
Her  udder  differs  from  that  of  the  cow  in  having  but  one  gland 
in  each  half.  There  are  from  two  to  four  cisterns  at  the  base 
of  the  teat  instead  of  one,  and  each  cistern  has  an  excretory 
canal  to  the  point  of  the  teat. 

Here  again  we  have  the  same  general  device  which  in  effect 
puts  a  thin  sheet  of  moving  blood  as  close  as  possible  to  a  thin 
sheet  of  epithelial  cells  supplying  the  latter  with  materials  for 
manufacture  and  with  this,  suitable  devices  for  holding  and  dis- 
posing of  the  product   (in  this  case  milk). 

A  cow's  udder  may  consist  largely  of  gland  tissue,  with  just 
enough  connective  tissue  to  support  it  and  hold  shape ;  it  may 
consist  largely  of  connective  tissue  with  a  relatively  smaller 
amount  of  gland  tissue.  AVhat  is  the  probable  structure  of  the 
udder  that  remains  large  and  hard  after  milking?  What  are 
some  of  the  reasons  why  small  udders  may  produce  well  and 
large  udders  produce  poorly? 

Note  the  large  vein  running  from  under  the  udder  forward 
under  the  belly.  This  is  the  abdominal  subcutaneous  vein  pre- 
viously mentioned ;  it  varies  greatly  in  size  and  shape,  and  drains 
the  inguinal  region,  including  the  udder.  What  possible  rela- 
tion is  there  between  the  size  of  this  vein  and  the  milk-produc- 
ing capacity  of  the  udder?  Why  is  a  very  large  vein  and  a 
large  opening  for  it  in  the  belly  wall  significant? 

What  effect  has  unusual  nerve  excitement  on  the  production 
of  milk?    Explain  this  effect. 

Disorders. — Disorders  of  the  udder  may  be  of  great  impor- 
tance even  though  slight  and  local.  Garget  may  refer  to  an 
unusual  congestion  or  to  a  true  inflammation  (mammitis),  in- 
volving the  mucous  membrane  of  the  milk  ducts,  alveoli,  and 
the  connective  tissue  framework  of  the  udder.     Injuries  to  the 


76  VETERINARY  STUDIES 

udder  and  teats  are  rather  common,  and  become  serious  by 
reason  of  infection.  Ohstructions  in  the  teat  duct  involve  the 
mucous  membrane  and  appear  in  the  form  of  small  tumors  or 
local  membranous  obstruction  or  as  a  general  thickening  of  this 
membrane. 

Many  of  these  cases  can  be  cured  by  a  veterinary  operation. 
Abscess,  due  to  infection,  may  destroy  a  considerable  amount  of 
gland  substance  and  is  treated  by  external  drainage  and  sur- 
gical cleanliness.  Cowpox  affects  the  skin  of  udder  and  teats 
and  resembles  smallpox.  It  is  usually  spread  by  the  milker's 
hands.  Upon  the  udder  where  not  broken  and  irritated  by  the 
milker's  hands,  there  is  first  a  sort  of  blister,  the  contents  of 
which  later  change  to  yellowish  pus,  thin  scab,  and  finally  a 
pitted  scar  for  each  blister. 

Suppression  of  milk  may  result  from  ill  health,  lack  of  nutri- 
tion, or  general  disease  of  the  udder,  and  there  appears  to  be  a 
suppression  of  bacterial  origin,  apparently  infectious. 

See  Udder  Diseases  and  Accidents,  Lecture  LVI. 


LECTURE  XV 
PATHOLOGY 

Physiology  is  the  study  of  the  body  organs  and  their  func- 
tions in  health. 

Pathology  is  the  study  of  diseased  organs  and  their  disordered 
functions.  Healthy  conditions  are  taken  as  a  basis  for  studying 
the  diseased  conditions.  Pathological  processes  are  but  healthy 
ones  modified. 

Hyperemia  (Congestion) 

Definition. — Hyperemia  is  an  abnormal  accumulation  of  blood 
in  any  part,  due  either  to  an  increased  inflow  or  a  decreased 
outflow.  The  color  of  an  hyperemic  part  may  be  distinctly  red 
in  active  hyperemia  or  bluish  in  passive  hyperemia. 

A  practical  example  is  congestion  of  the  lungs  of  a  fat  hog 
exercised  on  a  hot  day,  or  the  first  stage  of  founder  in  a  horse's 
foot,  or  the  congestion  of  a  cow's  udder  after  calving. 

There  are  two  kinds  of  hyperemia,  active  and  passive.  Gen- 
erally speaking,  both  types  are  local  conditions. 

Active  hyperemia  is  characterized  by  an  excessive  quantity  of 
blood  in  the  arteries  of  some  tissue  or  organ.  It  is  caused  by 
disturbances  of  the  arteriole  nerve  supply  (vasomotors),  i.e.  any 
agencies  that  produce  dilation  of  the  arteries,  as  body  tempera- 
ture disturbances,  chemical  irritants,  etc.  It  may  l)e  the  result 
of  lack  of  lilood  elsewhere  in  the  body ;  e.g.  sudden  chilling  of 
the  skin  of  a  horse  frequently  produces  active  hyperemia  of  the 
lung  or  other  internal  organs.  Active  hyperemia  is  usually  tem- 
porary, and  permanent  injury  may  be  slight  or  may  not  occur. 
As  a  rule  a  part  so  affected  is  red,  warm  and  dry.  An  active 
hyperemia  may  lead,  if  long  continued,  to  enlargement  of  the 
part  or  organ.  The  vessels  themselves  may  enlarge  to  several 
times  their  former  size. 

Passive  hyperemia,  passive  congestion  (venous  or  mechani- 
cal), is  a  condition  in  which  the  current  of  venous  blood  is 
obstructed,  outflow  is  decreased,  and  blood  accumulates  in  veins 

77 


78  VETERINARY  STUDIES 

and  capillaries.  An  organ  so  affected  is  apt  to  be  bluish  in 
color,  spongy,  moist  and  cool.  This  condition  may  be  due  to 
weakened  heart  action,  or  to  obstruction  in  veins,  and  less  fre- 
quently to  obstruction  in  arteries  or  capillaries.  Some  of  the 
local  changes  that  may  follow  passive  congestion  are  exudation 
of  serum  (dropsy),  abnormal  development  of  connective  tissue, 
clots  in  the  vessels,  and  local  tissue  death  (necrosis). 

Anemia 

Definition. — Anemia  is  an  abnormal  condition  characterized 
by  a  deficiency  of  total  volume  or  a  deficiency  of  corpuscles. 
Anemia  due  to  deficiency  may  be  either  general  or  local.  Dis- 
turbances of  the  nerve  fibers  (vasomotors)  which  control  the 
involuntary  muscle  fibers  of  the  blood  vessels  have  the  same 
relation  to  anemia  as  to  hyperemia.  By  contracting  or  relaxing, 
the  muscle  fibers  decrease  or  increase  the  size  and  therefore,  the 
holding  capacity  of  the  blood  vessels. 

General  anemia. — This  refers  to  a  state  of  ill  health  charac- 
terized by  general  lack  in  total  volume  of  blood  or  to  a  lack  in 
relative  number  of  corpuscles.  This  may  be  caused  by  hemor- 
rhage, poor  nutrition,  destruction  of  red  cells,  as  by  chemical 
poisons  or  by  bacterial  toxins,  or  disorder  of  blood-forming 
tissues.  General  anemia  is  seen  in  the  horse  disease  known  as 
swamp  fever,  where  the  mucous  membranes  become  pale,  or  in 
a  case  of  castration  when  the  colt  bleeds  badly. 

Local  anemia. — Local  anemia  may  be  due  to :  decreased  inflow 
or  increased  outflow ;  for  example,  pressure  upon  the  part ;  con- 
traction of  arteries  supplying  this  part;  excessive  blood  else- 
where in  the  body;  cold  or  chemical  agents.  In  such  cases  the 
organ  is  pale,  flabby  and  dry,  and  it  does  not  bleed  normally 
when  cut. 

Results. — Either  anemia  or  passive  congestion  results  in  tis- 
sue starvation,  deprivation  of  oxygen  and  accumulation  of  waste, 
and  the  seriousness  depends  upon  extent,  location  and  duration. 
An  anemia  may  be  very  serious  in  vital  organs  or  much  less 
important  in  such  organs  as  the  skin  and  muscles.  During 
anemia,  nutritive  changes  are  restricted  and  the  processes  of 
excretion  are  checked.     Waste  products  therefore  accumulate. 

Complete  and  persistent  anemia  results  in  death  of  the  tissue 
(necrosis). 


PATHOLOGY  79 


Inflammation 


Definition. — Inflammation  is  the  protective  and  curative  re- 
sponse of  any  tissue  to  an  injury.  It  is  a  complex  pathological 
process  consisting  of  disturbances  of  circulation,  and  construc- 
tive and  destructive  tissue  changes.  Pain,  heat,  redness,  swell- 
ing and  impairment  of  function  are  the  symptoms  of  inflamma- 
tion. These  may  be  slight  and  not  evident  in  mild  and  chronic 
inflammation. 

The  changes  which  occur  in  the  blood  vessels  during  inflam- 
mation as  in  pneumonia  for  example  are:  (1)  dilation  of  small 
arteries,  capillaries,  and  veins;  (2)  increased  current  velocity  at 
first,  then  decreased;  (3)  obstruction  of  the  blood  current,  due 
to  the  collecting  of  corpuscles  in  the  capillaries  and  small  veins, 
and  the  adherence  of  white  corpuscles  to  their  walls;  (4)  when 
the  velocity  of  the  blood  begins  to  decrease,  both  kinds  of  cor- 
puscles and  the  blood  plasma  may  pass  through  the  walls  of 
small  veins  and  capillaries,  i.e.,  exudation.  Thus  the  bronchioles 
and  air  cells  become  filled  in  a  case  of  pneumonia. 

The  changes  in  an  inflamed  tissue,  the  udder  for  instance,  are 
variable.  In  the  beginning  of  an  inflammation,  the  causing 
agent  produces  cell  degeneration,  and  in  some  instances  cell 
death,  whereas  in  the  later  stages  of  inflammation  there  may  be 
cell  multiplication  and  regeneration  of  tissue  as  in  the  healing 
of  a  wound. 

Inflammation  varies  according  to  (a)  resisting  power  of  tis- 
sue, (6)  activity  of  cause,  (c)  length  of  time  the  cause  is  in 
action. 

Causes  of  inflammation. — Inflammation  maj'  be  caused  by 
mechanical  injury,  such  as  barb-wire  cut ;  by  chemical  action  as 
in  careless  burn  of  the  skin  by  caustic  potash,  in  dehorning 
young  calves;  by  excessive  tissue  activity,  e.g.,  a  badly  over- 
worked kidney  caused  by  an  overdose  of  turpentine ;  injury  by 
extremes  of  heat  and  cold,  or  by  toxins  from  bacteria  or  from 
dead  tissue.  Inflammation  thus  caused  has  little  tendency  to 
spread  beyond  the  part  injured,  and  there  is  usually  little  or  no 
pus  unless  germs  invade  the  inflamed  area. 

"Microbes,"  "microorganisms,"  "bacteria,"  and  "germs" 
are  synonymous  terras  as  commonly  used.  These  can  cause 
inflammation  without  the  aid  of  other  local  injury  as  for  ex- 
ample, a  suppurative  (pus)  inflammation  of  glands  in  the  throat 


80  VETERINARY  STUDIES 

of  a  colt  that  has  distemper,  or  a  nonsuppurative  inflammation 
in  the  shoulder  of  a  calf  which  has  been  affected  by  black  leg. 
Such  inflammation  is  more  commonly  caused  by  irritant  chemi- 
cal agents  which  the  germs  manufacture. 

Terminations. — Inflammation  may  terminate  in  (a)  resolu- 
tion and  regeneration,  (b)  degeneration  and  death  of  the  tissue, 
or  (c)  new  growths. 

In  case  of  resolution,  the  exudate  is  liquefied  and  removed  by 
the  lymphatics  and  veins,  or  it  is  carried  out  by  leucocytes 
(white  corpuscles).  The  blood  current  then  starts  again  in  the 
small  vessels ;  the  corpuscles  move  away  in  the  reestablished 
current,  or  else  become  degenerated  and  are  removed ;  and,  thus 
the  organ  or  tissue  becomes  approximately  normal  again.  There 
is  usually  some  new  tissue  formation. 

Local  death. — If  death  of  the  part  occurs,  tissues  may  be  dis- 
solved and  absorbed  if  small  in  amount,  or  the  part  may  slough, 
i.e.,  separate  from  healthy  tissue  as  in  case  of  a  frozen  ear.  In- 
flammation may  extend  to  and  involve  surrounding  tissues,  and 
thus  the  life  of  the  animal  may  be  ultimately  destroyed,  as  in 
extensive  gangrene  of  a  cow's  udder. 

If  new  growths  occur,  there  develop  new  tissues,  e.g.,  tumors, 
granulations  in  a  wound,  and  scar  tissue,  as  in  case  of  large  foot 
resulting  from  a  wire  cut  in  a  horse. 

Fever 

Definition. — Fever  is  an  abnormal  condition  characterized  by 
an  excess  of  heat  in  the  body.  It  is  not  a  disease,  but  merely 
a  symptom  of  disease.  Fever  is  usually  a  defensive  response 
to  an  attack,  for  example,  an  infection,  which  produces  dan- 
gerous toxins,  the  higher  temperature  being  unfavorable  to  the 
causative  germs. 

Cause. — Fever  results  from  any  disturbance  that  causes  an 
increase  of  heat  production  or  decrease  of  heat  loss,  usually  the 
former.  It  should  be  distinguished  from  overheat,  the  former 
being  an  increased  body  temperature  due  to  increased  heat  pro- 
duction within  the  body  or  to  decreased  heat  loss.  In  overheat 
there  is  an  excessively  high  body  temperature  not  the  result 
of  disturbance  of  heat  production  or  heat  dissipation,  but  caused 
by  absorption  and  accumulation  of  heat  from  without. 

The  normal  temperature  of  horse  is  100  to  101.5  degrees  F. 


PATHOLOGY  81 

One  hundred  and  four  degrees  F.  is  called  high,  106  degrees  F. 
very  high.  Normal  temperature  of  adult  cattle  varies  from  100 
to  102.5  degrees;  of  sheep  from  100  to  101  degrees.  The  ner- 
vous system  has  control  of  body  temperature  through  heat  pro- 
duction and  heat  loss,  increasing  or  decreasing  production  by 
tissue  oxidation,  and  increasing  or  decreasing  loss  through  con- 
trol of  the  amount  of  blood  sent  to  the  surface  of  the  body,  more 
or  less  perspiration,  etc.  The  body  temperature,  like  the  tem- 
perature of  a  room,  is  therefore  a  balance  between  heat  produc- 
tion and  heat  loss. 

Heat  production. — The  source  of  animal  heat  is  the  oxidation 
of  body  tissue  and  fuel  materials  in  the  blood  and  the  conse- 
quent breaking  up  of  complex  chemical  compounds  into  simpler 
ones.  The  principal  heat-furnishing  organs  are  the  most  active 
organs,  e.g.,  the  muscles  and  secreting  glands. 

Heat  expenditure. — Body  heat  is  normally  expended  about  as 
follows:  warming  food  and  drink,  2  per  cent;  warming  air  in 
lungs,  5  per  cent;  evaporation  from  lungs,  8  per  cent;  evapora- 
tion of  moisture  from  the  skin  surface  and  radiation  from  skin, 
85  per  cent.  The  expenditure  of  heat  in  evaporation  of  moisture 
from  the  skin  surface  is  very  much  larger  than  in  either  of  the 
others.  On  an  average  there  is  sufficient  heat  developed  daily  in 
the  body  of  a  medium-sized  horse  to  raise  4550  gallons  of  water 
1.8  degrees  F. 

Symptoms  of  fever. — Chill  and  elevation  of  temperature;  dry, 
hot  skin;  quickened  pulse  and  respiration  (normal  pulse  of 
horse,  36  to  45;  normal  respiration  8  to  14  per  minute)  ;  scanty 
urine,  and  checked  secretions  in  general,  milk,  perspiration,  etc. ; 
loss  of  flesh  and  constipation,  are  symptoms  of  fever. 

Kinds  of  fever. — Classified  according  to  course,  the  kinds  of 
fever  are:  (a)  continuous,  with  but  slight  variation  in  tem^jera- 
ture,  (&)  remittent,  the  temperature  varies  greatly  during  the 
day,  but  does  not  descend  to  normal;  (c)  intennittent,  the  tem- 
perature varies  at  different  portions  of  the  day  and  reaches  nor- 
mal each  day;  and  (d)  relapsing,  the  fever  recurs  at  intervals, 
with  periods  of  one  or  more  days  of  normal  temperature  be- 
tween. 

Results. —  (a)  Emaciation,  or  general  atrophy,  which  is  more 
or  less  severe,  according  to  the  duration  and  height  of  the  fever, 
and  is  caused  by  continued  unusual  oxidation  of  body  tissues 
during  the  fever;  (&)  death  may  occur;  or  (c)  recovery  may  be 


82  VETERINARY  STUDIES 

made.  The  recovery  may  be  partial  or  complete,  slow  or  rapid, 
depending  on  the  nature  of  the  disease  of  which  the  fever  is  a 
symptom  or  condition;  the  native  vigor  or  vital  constitution 
of  the  patient;  and  the  conditions  under  which  the  patient  is 
kept  and  under  which  the  disease  runs  its  course. 

Practical  application. — The  student  may  now  understand  that 
pam  accompanying  inflammation  may  be  a  useful  protection, 
and  that  it  is  due  to  a  stretching  of  sensory  nerve  fibers,  to  pres- 
sure on  these  fibers,  or  to  irritation  by  bacterial  or  tissue  prod- 
ucts. The  heat  is  clearly  due  to  increased  tissue  activity  and, 
therefore,  increased  oxidation;  the  redness  to  hyperemia;  the 
swelling,  to  engorgements  and  exudation  of  the  blood;  and  the 
impaired  function  to  interference  with  normal  tissue  activity 
by  these  several  conditions. 

It  is  important  that  the  student  understand  what  the  possible 
terminations  of  an  inflammation  may  be;  and  what  the  factors 
are  which  affect  regeneration  and  resolution,  as  in  a  recovered 
garget ;  or  degeneration  and  necrosis,  as  in  abscess  or  gangrene 
of  an  inflamed  udder ;  or  which  lead  to  new  growth,  as  in  a  big 
foot  following  wire  cut.  Obviously,  lack  of  nutrition,  poor  cir- 
culation, destructive  medicines,  etc.,  tend  toward  tissue  degen- 
eration and  necrosis;  whereas  vitality,  good  food,  tonics,  and 
proper  local  treatment  favor  regeneration,  resolution,  and  re- 
covery. Irritating  medicine  on  a  wound  of  the  foot  where  there 
is  a  natural  tendency  to  over-regeneration  can  only  make  the 
matter  worse. 

It  is  important,  also,  to  remember  that  hyperemia,  inflamma- 
tion, fever,  etc.,  within  reasonable  limits,  are  protective  and 
curative,  but  that  beyond  such  limits  they  may  be  destructive. 
It  should  now  be  clear  to  the  student  why  it  is  dangerous  to 
work  a  horse  that  is  suff'ering  from  fever,  as  in  a  mild  dis- 
temper, because  there  is  already  abnormal  oxidation,  and  work 
increases  it.    The  excretory  organs,  too,  are  already  overworked. 


LECTURE  XVI 
PATHOLOGY— Co^^inwed 

Hemorrhag"e. — Any  escape  of  blood  from  its  natural  channels, 
whetlicr  into  the  tissues,  or  cavities,  or  upon  the  body  surface, 
is  termed  "hemorrhage." 

Cannes. — Hemorrhage  is  caused  by  injury  to  the  vessel  walls, 
as  when  cut  or  torn ;  diseases  of  the  vessel  walls,  such  as  fatty 
or  calcareous  degeneration ;  bacterial  toxins,  injuring  the  capil- 
laries; excessive  blood  pressure  inside  the  vessel,  as  in  hyper- 
trophy of  the  heart  with  excessive  strength  and  activity,  result- 
ing in  rupture  of  the  vessels ;  change  i"  the  quality  of  the  blood, 
with  weakness  in  the  vessel  walls,  as  in  purpura,  a  common 
disease  of  horses. 

Dropsy. — Any  abnormal  collection  of  serous  fluid  in  any  cav- 
ity or  tissue  of  the  body  is  designated  as  "dropsy."  This  may 
occur  in  the  abdominal  cavity,  in  the  chest  cavity,  ventricles  or 
the  brain,  or  the  loose  tissues  under  the  skin.  Of  those  places 
outside  the  large  cavities,  the  most  common  are  the  limbs  and 
lower  portions  of  the  abdomen,  as  the  swelling  under  the  belly 
of  a  mare  heavy  with  foal  and  lacking  exercise,  or  a  swelling 
of  sheath  and  belly  in  a  case  of  recent  castration  with  infection 
and  lack  of  exercise.  Dropsical  fluid  is  usually  of  a  pale  straw 
color,  nearly  neutral  in  chemical  reaction,  and  slightly  heavier 
than  water. 

Cause  of  dropsy. — Any  local  increase  of  blood  pressure ;  any 
interference  with  flow  of  blood  in  the  veins;  or  obstruction  in 
capillaries,  which  is  quite  common  in  diseases  of  the  liver  or 
kidneys  will  cause  dropsy.  Note  the  similarity  of  these  causes 
to  the  causes  of  passive  hyperemia.  Dropsy  may  be  either 
general  or  local. 

General  dropsy  may  be  due  to  conditions  associated  with 
anemia,  passive  hyperemia,  heart  trouble,  or  kidney  disease, 
and  may  affect  the  subcutaneous  connective  tissue  over  a  large 
area,  and  any  of  the  serous  body  cavities. 

Local  dropsy  is  limited  to  some  one  organ  or  cavity,  and  it 

83 


84  VETERINARY  STUDIES 

may  be  due  to  local,  mechanical  obstruction  in  the  veins  or  lym- 
phatic vessels,  producing- sluggish  circulation,  as  in  the  "stock- 
ing" of  the  horse's  hind  leg. 

Hypertrophy. — The  term  "hypertrophy"  is  applied  to  any 
enlargement  of  any  part  or  organ  of  the  body.  It  may  be  due 
to  either  an  increase  in  the  number  of  elements,  or  to  an  increase 
in  the  size  of  existing  elements,  or  to  a  combination  of  these 
two  conditions.  Hypertrophy  may  be  either  physiological, 
healthy,  or  pathological,  diseased.  The  cause  may  be :  continued 
increase  of  nutrition  in  a  mild  active  hypermia,  or  moderately 
increased  use  as  in  a  muscle,  or  the  presence  of  unknown  factors 
probably  internal  secretions,  such  as  an  enlargement  of  the  mam- 
mary gland  in  pregnancy. 

Physiological  hypertrophij  is  illustrated  in  the  blacksmith's 
arm,  where  there  is  enlargement  of  muscles  due  to  an  increased 
exercise  and,  therefore,  increased  nutrition  to  the  muscles.  If 
one  kidney  be  removed,  the  other  enlarges  to  compensate. 

PatJiological  hypertrophy  is  illustrated  in  "elephant  leg" 
(lymphangitis)  of  horses,  a  condition  in  which  the  connective 
tissue  of  the  skin  and  underlying  parts  increases  in  quantity, 
resulting  in  general  enlargement  of  the  leg. 

In  any  hypertrophy  the  newly  formed  elements  are  more 
nearly  like  the  normal  when  the  circulation  is  most  vigorous. 

Atrophy. — This  is  the  opposite  of  hypertrophy  and  is  charac- 
terized by  decrease  in  bulk  and  weight,  as,  for  instance,  sweeny 
of  the  shoulder  muscles  in  horses.  Atrophy  may  be  general  or 
local,  and  the  decrease  in  size  may  be  due  either  to  decrease 
in  size  or  number,  or  to  decrease  both  in  size  and  number  of  the 
elements. 

The  seriousness  of  this  depends  upon  its  extent  and  the  part 
involved.  Atrophy  of  a  nerve  trunk  means  paralysis  of  func- 
tion. Atrophy  of  a  shoulder  may  not  be  very  serious,  and  the 
part  may  easily  recover. 

Local  atrophy,  e.g.,  contracted  hoof,  or  shoulder  sweeny,  may 
be  caused  by :  decrease  in  amount  of  blood  and  nutrition ; 
a  nerve  disturbance,  which  sometimes  results  in  very  rapid 
atrophy ;  inflammation  interfering  with  circulation  and  nutri- 
tion ;  insufficient  activity  or  excessive  activity  and  exhaustion 
of  the  tissue  elements  which  are  thus  worn  out  faster  than  they 
are  rebuilt;  continuous  pressure  resulting  in  anemia  and  local 
starvation. 


PATHOLOGY  85 

General  atrophy  may  be  caused  by  lack  of  nutrition  or  ex- 
cessive consumption  and  wastage  of  the  soft  tissues,  especially 
of  the  fats  which  are  first  taken ;  as  in  typhoid  fever  in  the 
human  body,  or  intiuenza  in  the  horse.  In  this  sense,  general 
atrophy  is  synonymous  with  emaciation. 

Degenerations  and  infiltrations.— These  are  characterized  by 
changes  in  the  quality  of  a  tissue ;  the  bulk  may  or  may  not 
remain  the  same.  In  general  when  tissue  degenerates,  a  cheaper 
material  is  deposited  in,  and  replaces  tissue  already  diseased  as 
a  rule.  When  infiltration  occurs,  the  lower  grade  tissue  is  de- 
posited between  and  later  into  the  tissue  elements,  which  at 
the  time  are  otherwise  normal  as  a  rule,  e.g.,  the  fat  old  house 
dog  or  pet  horse.  The  proper  elements  ma}'  subsequently  shrink. 
In  either  case  the  affected  organ  loses  in  usefulness.  The  causes 
of  these  degenerative  changes  are  numerous,  but  they  are  closely 
related,  e.g.,  abnormal  use  or  disuse,  i.e.,  disturbance  of  function ; 
heredity ;  disturbance  of  nutrition,  excess  or  deficiency,  usually 
the  latter ;  or  certain  poisons.  No  sharp  line  can  be  drawn  be- 
tween infiltration  and  degeneration.  Possibly  they  should  be 
regarded  as  stages  of  the  same  process. 

Fatty  degeneration  is  characterized  by  the  development  of 
fatty  matter  in  tissue  cells,  already  diseased  as  a  rule,  and 
replacing  the  proper  tissue  elements.  This  is  especially 
common  in  muscular  and  glandular  tissue,  e.g.,  heart  and 
liver. 

Fatty  infiltration  is  characterized  by  a  deposit  of  fatty  matter 
between  the  tissue  elements  and  later  in  tissue  cells. 

Calcareous  degeneration  and  infiltration  are  marked  by  de- 
posit of  lime  salts  generally  in  tissues  already  diseased,  as  tuber- 
culous lymph  glands,  and  may  be  caused  by  any  agency  that 
results  in  imperfect  nutrition  and  lessened  vitality.  These  con- 
ditions occur  more  frequently  in  the  tissues  of  older  people  or 
animals.  The  muscular  coat  of  the  arteries  sometimes  becomes 
calcified  and  brittle  in  old  people  and  may  even  break  under 
unusual  strain. 

Cells  normally  cartilage  often  deposit  calcium,  forming  bone 
as  in  the  lateral  cartilages  of  the  horse's  foot,  causing  lameness 
and  the  unsoundness  known  as  side  bone.  There  are  various 
other  degenerations  and  infiltrations  besides  these  two  named; 
but  in  each  case  there  occurs  the  deposit  of  some  inferior  tissue 
into  or  between  the  proper  elements  of  the  organ. 


86  VETERINARY  STUDIES 

Collapse. — The  symptoms  of  collapse  are:  temperature  below 
normal ;  surface  of  the  body  cold ;  respirations  are  very  shallow 
and  slow ;  and  the  pulse  is  feeble  and  very  slow  or  very  fast. 

Collapse  may  be  the  result  of:  very  high  fever,  poison,  sup- 
pression of  secretion  or  excretion,  rupture  of  internal  organs, 
excessive  hemorrhage. 

Syncope. — This  term  signifies  a  suspension  of  heart  action. 
It  is  more  sudden;  the  symptoms  are  more  brief  than  in  col- 
lapse, and  it  is  usually  due  to  obstruction  in  the  nutrient  arteries 
to  the  heart. 

Death. — This  condition  may  be  general  or  only  local.  When 
general,  there  is  a  permanent  arrest  of  all  functions.  Death  may 
begin  in  the  heart,  lungs,  or  brain.  Heart  failure  (syncope) 
is  very  sudden.  Lung  failure  results  in  suffocation  or  asphyxia. 
Brain  failures  develop  slow  symptoms,  stupor  being  present. 
When  death  occurs  because  the  blood  is  altered,  the  heart  is  the 
first  organ  to  cease  action. 

Necrosis  or  local  tissue  death  is  seen  in  ulcers,  frozen  parts, 
abscess,  etc.  It  is  caused  by  local  disturbance  of  nutrition, 
starvation ;  or  by  disturbance  of  circulation,  as  in  anemia,  pas- 
sive hyperemia  or  inflammation.  It  may  be  caused  by  bacterial 
toxins,  caustic  medicine,  an  injury  or  a  bruise. 

Practical  application  and  suggestion. — It  is  evident  that  the 
student  can  have  no  intelligent  conception  of  any  disease  until 
he  knows  something  of  such  pathological  processes  as  inflamma- 
tion, dropsy,  degeneration,  etc.,  which,  together,  constitute  the 
disease.  With  this  in  mind,  diseases  like  sidebone,  sweeny,  and 
abscess  become  clear. 

Many  disorders  may  be  averted  when  one  can  foresee  and 
change  an  unfavorable  condition  to  a  favorable  one.  To  illus- 
trate, a  heavy  horse  whose  foot  is  too  high  on  the  inside  puts 
excess  weight  against  the  outer  lateral  cartilage,  causing  irrita- 
tion, inflammation,  and  side  bone.  Leveling  the  foot  will  pre- 
vent the  occurrence  of  this  trouble. 

An  inflammation  may  be  caused  by  excess  functional  activity, 
for  example,  overwork  as  when  a  horse  gets  a  nail  puncture  in 
the  right  foot,  causing  him  to  overwork  the  left  foot,  so  that 
founder,  which  is  an  inflammation  of  the  sensitive  lamina?, 
results.  The  possibility  of  this  condition  should  be  anticipated, 
and  prevented  by  inducing  the  horse  to  lie  down,  or  by  supply- 
ing him  with  soft  bedding  like  sawdust,  or  by  the  use  of  slings. 


PATHOLOGY  87 

Hemorrhage  may  vary  from  an  almost  invisible  dot  to  a 
serious  loss  of  blood.  It  may  occur  in  practically  any  tissue, 
under  any  membrane,  and  in  any  cavity ;  or  it  may  occur  upon 
the  body  surface.  A  tiny  pin-point  hemorrhage  may  be  very 
sigiiificant  on  the  kidney  in  case  of  hog  cholera,  for  example. 
About  one-fifteenth  of  the  animal's  weight  is  blood;  and  one- 
half  of  this  may  be  lost  without  necessary  death. 

Dropsy  results  when  there  is  a  disturbance  of  the  normal 
balance  between  the  movement  of  serum  from  the  capillaries 
into  tlie  lymph  spaces,  and  from  these  spaces  into  thx,  iymph 
vessels,  so  that  serum  accumulates  in  lymph  spaces.  An  ex- 
ample of  this  condition  is  the  "stocking"  of  the  horse  which 
stands  in  the  stable.  "Stocking"  disappears  with  exercise  and 
normal  circulation. 

The  seriousness  of  atrophy  depends  upon  its  extent  and  loca- 
tion. Atrophy  is  frequently  due  to  trouble  elsewhere,  which, 
if  not  understood,  leads  to  treatment  at  the  wrong  point.  For 
example,  a  horse  steps  on  a  nail,  goes  lame,  and  has  a  sweeny 
at  the  shoulder.     The  first  place  for  treatment  is  in  the  foot. 

Degenerations  usually  affect  tissues  which  are  already  diseased. 
Serious  or  even  fatal  degeneration  is  prevented  by  anticipating 
and  preventing  the  original  trouble. 


LECTURE  XVII 
WOUNDS 

A  wouna  is  a  sudden  break  in  the  continuity  of  a  tissue, 
caused  by  external  violence. 

Healing. — All  wounds  heal  by  the  production  of  new  cells  and 
new  intercellular  substance  formed  from  preexisting  tissue 
cells.  The  embryonic  cells  change  later  into  mature  cells  like 
those  of  the  adjacent  tissue.  Complete  union  implies  a  restora- 
tion of  circulation  and  nutrition.  This  again  implies  new  blood 
vessels  for  the  new  tissue. 

Union  ly  primary  intention. — The  essential  features  of  this 
mioiie  are  rapiQ  union  and  the  absence  of  germs  and  pus.  All 
wounds  which  heal  without  suppuration  heal  in  this  way.  There 
is  always  some  new  tissue  formed,  although  it  may  not  be  visible. 

By  granulation. — This  is  observed  in  the  healing  of  open 
wounds  and  consists  of  the  formation  of  new  tissue  by  the 
multiplication  of  preexisting  cells.  This  new  tissue  fills  the 
space  between  the  wound  margins  and  replaces  the  tissue  that 
was  destroyed. 

Newly  formed  tissue  in  open  wounds  is  composed  of  capil- 
laries, embryonic  connective  tissue  cells,  and  leucocytes.  If  the 
wound  is  free  from  harmful  bacteria  and  the  surfaces  are  kept 
at  rest  and  close  together,  healing  is  very  rapid  and  but  little 
new  tissue  is  needed.  Where  there  is  loss  of  much  tissue,  how- 
ever, it  may  be  impossible  to  bring  the  surfaces  together  and  a 
great  deal  of  new  tissue  is  needed.  Connective  tissue  cells  de- 
velop from  preexisting  connective  tissue  cells,  and  epithelial 
from  epithelial,  bone  from  bone,  etc. 

When  wounds  are  covered  with  granulations,  each  little  eleva- 
tion contains  a  loop  or  network  of  new  blood  vessels.  The 
white  blood  corpuscles  emigrate  through  the  new  blood  vessels 
and  form  part  of  the  pus,  when  pus  is  present.  Healthy  granu- 
lations are  small,  firm,  pink  in  color,  and  the  surface  is  slightly 
moistened  with  a  colorless  fluid.  In  this  case  the  wound  heals 
rapidly  and  usually  leaves  a  small  scar. 

88 


WOUNDS  89 

Proud  flesh  is  merely  a  mass  of  profuse  granulations,  and  in- 
dicates either  a  lack  of  vitality  or  else  external  irritation.  The 
latter  is  iLsually  caused  by  germs. 

Development  of  new  blood  vessels. — New  blood  vessels  de- 
velop from  vessels  that  jjreviously  existed  in  the  injured  tissue. 
The  growth  of  new  blood  vessels  and  new  tissue  for  union  start 
together  and  continue  until  enough  granulation  tissue  has  been 
developed  to  fill  the  wound  gap.  The  new  vessels  start  by 
budding  from  capillaries  near  the  surface,  and  are  always  short. 
These  buds  project  farther  and  farther  and  gradually  change 
into  threads,  which  gradually  hollow  into  tubes,  beginning  at 
the  end  near  the  old  capillary.  It  happens  frequently  that  the 
ends  of  two  neighboring  projections  meet  and  unite  to  form  an 
arch.  As  this  becomes  hollowed  out,  a  capillary  loop  is  formed. 
When  the  development  is  complete,  then  new  blood  vessels  may 
start  from  this  one  and  perhaps  develop  another  arch.  The 
thread-like  projections  are  probably  hollowed  out  by  tne  blood 
current  in  the  parent  vessel. 

Granulation  tissue  in  the  beginning  is  more  vascular  than 
normal  tissue,  in  fact,  largely  a  tuft  of  capillaries.  Useless 
vessels  are  constricted  and  finally  obliterated. 

Inflammation  in  wounds  is  due  to  foreign  material;  for  in- 
stance, dead  tissue  or  foreign  bodies,  but  more  commonly  to 
germs  which,  by  multiplication,  give  rise  to  wound  infection 
and  inflammation. 

Osseous  tissue. — Wounds  in  bone  tissue  heal  in  the  same  w^ay 
as  those  in  other  tissues,  the  wound  surface  being  covered  with 
granulations.  The  development  of  new  tissue  is  from  the  perios- 
teum and  from  the  marrow  at  the  place  of  injury.  At  the 
end  of  a  few  weeks,  the  ends  are  united  by  a  spongy  mass  be- 
neath the  periosteum  and  in  the  medullary  canal.  This  mass, 
called  a  callus,  gradually  becomes  organized,  and  later,  is  partly 
removed. 

Cartilage. — On  account  of  low  nutrition  cartilage  has  very 
little  power  of  repair.  Loss  of  cartilage  is  generally  repaired  by 
fibrous  connective  tissue. 

Nerve  tissue.— After  a  nerve  is  cut,  the  severed  portion  de- 
generates. New  axis  cylinders  come  down  from  the  stump  and 
grow  through  or  along  old  sheaths  of  the  severed  portion.  It 
is  doubtful  whether  ]irimary  union  ever  takes  place.  Quick 
return  of  sensibility  does  not  necessarily  imply  restoration  of 


90  VETERINARY  STUDIES 

the  injured  fibers.  The  newly  grown  axis  cylinders  receive 
sheaths  which  probably  grow  from  nerve  cells  lying  within  the 
old  sheaths.  Whether  the  new  fibers  ever  reach  the  old  terminals 
depends  upon  the  amount  of  intervening  tissue  and  the  density 
of  it.    The  limit  of  growth  is  placed  at  from  one  to  two  inches. 

The  new  tissue. — In  certain  tissues,  extensive  injuries  may 
be  repaired  by  tissue  which  closely  resembles  the  original.  This 
is  true  of  connective  tissue,  skin,  tendons,  and  bones.  Muscular 
tissue  seems  to  have  much  less  ability  to  repair  extensive  in- 
juries and  repairs  partly  by  connective  tissue  in  place  of  the 
original  muscle.  Scar  tissue  contracts  for  a  long  time  after 
healing  is  complete.  The  scar  is  large  when  there  has  been 
more  granulation  tissue  than  necessary,  as  in  foot  wounds,  or 
where  an  extensive  removal  of  tissue  necessitates  a  great  amount 
of  scar  tissue.  Scar  tissue  in  this  case  is  endowed  with  low 
vitality,  and  is  poorly  nourished. 

How  skin  recovers  a  surface. — A  -wound  is  not  entirely  healed 
until  it  is  recovered.  This  takes  place  by  development  of  new 
epithelial  cells  from  those  of  the  skin.  These  new  epithelial 
cells  gradually  form  new  skin  which  grows  from  the  margin. 
It  covers  the  granulations  loosely  at  first,  but  later  unites  firmly 
with  them.  New  epithelial  cells  have  the  power  of  ameboid 
movement.  They  may  become  detached  from  the  margin  and 
set  up  a  new  covering  center  elsewhere  on  the  wound  surface; 
in  fact  skin  and  other  tissue  cells  may  be  kept  alive  a  long  time 
under  suitable  conditions  for  transplanting.  Restoration  of  the 
skin  surfaces,  and  for  that  matter  the  entire  healing,  is  favored 
by  rest  and  surgical  cleanliness,  and  is  hindered  by  infection 
and  injurious  bacterial  products,  poor  nutrition,  and  irritating 
medicines,  and  the  rubbing  of  sponges,  etc.,  over  the  surface. 

An  exception  should  be  noted;  viz.,  that  when  healing  has 
ceased  in  case  of  an  old  sore,  with  the  surface  not  yet  covered 
by  skin,  healing  may  sometimes  be  given  a  vigorous  start  by  a 

blister. 

Many  of  the  preparations  commonly  used  by  stockmen  do 
much  more  harm  than  good. 


LECTURE  XVIII 
WOUNDS— Ca/i^mi^e^ 


The  most  common  wounds  which  affect  stock  are  those  caused 
by  barbed  wires,  plows,  harrows,  etc.,  and  are  generally  large 
and  badly  torn.  The  farmer  rarely  has  to  deal  with  a  clean 
wound  that  can  unite  smoothly  and  heal  rapidly-. 

Bad  treatment. — Nearly  every  farmer  has  some  special  dope 
which  he  thinks  of  great  value  in  the  treatment  of  wounds ;  how- 
ever, most  of  these  prepara- 
tions are  seriousl}'  injurious 
and  greatly  retard  healing. 
Various  preparations  of  tur- 
pentine, alcohol,  vinegar, 
carbolic  acid,  strong  coal  tar 
dips,  dirty  cobwebs,  irritat- 
ing oils,  and  even  the  min- 
eral acids  are  frequently 
used  in  the  treatment  of 
these  wounds ;  and  then,  be- 
cause the  patient  recovers  in 
spite  of  barbarous  treat- 
ment, people  erroneously 
conclude  that  the  medicine 
cured. 

Bleeding. — This  can  usu- 
ally be  ciiecked  quite  easily. 
If  the  blood  comes  from  a 
large  number  of  small  ves- 
sels, the  hemorrhage  can  be 

checked  and  finally  stopped  by  means  of  ice,  or  very  cold  or 
very  warm  water;  or  the  wound  may  be  packed  with  clean 
cotton  or  oakum  and  tightly  bandaged.  In  case  a  large  blood 
vessel  is  severed,  it  may  be  better  to  draw  the  end  out  and  tie 
a  strong   thread   around   it.     The   artery   may  be  secured  by 

91 


Fig  35. — Badly  Treated  Wire 
Wound.     (M.  H.  R.) 


92  VETERINARY  STUDIES 

means  of  small  forceps  or  even  with  a  hook  made  by  bending  a 
pin  or  piece  of  wire. 

In  some  cases  hemorrhage  can  be  easily  controlled  by  a  tight 
bandage  placed  above  or  below  the  wound.  If  the  blood  flows 
in  a  steady  stream,  the  bandage  should  be  on  the  side  farthest 
from  the  heart.  If  it  flows  in  jets,  the  bandage  should  be  tied 
between  the  wound  and  the  heart. 

Ergot  and  other  medicines  given  internally  constrict  blood 
vessels  and  aid  in  checking  hemorrhage.  If  a  calf  should 
bleed  seriously  after  castration,  the  scrotum  may  be  firmly 
packed  with  a  strip  of  gauze  or  clean  muslin  and  temporarily 
tied.  If  bleeding  has  been  serious  and  the  heart  is  weak,  a 
stimulant  like  camphor  dissolved  in  olive  oil  may  be  given  by 
hypodermic  syringe  under  the  skin. 

Sewing. — Comparatively  few  Avounds  are  materially  benefited 
by  sewing  or  bandaging,  except  by  professional  hands.  If  the 
wound  is  made  lengthwise  of  the  muscle,  there  may  be  consid- 
erable advantage  in  holding  the  sides  together  by  sewing.  No 
special  form  of  needle  or  thread  is  necessary  except  that  both 
should  be  clean,  and  the  latter  should  be  of  reasonable  size. 
A  darning  needle  and  ordinary  white  cotton  thread  or  twine 
will  do  in  an  emergency.  But  if  the  wound  is  made  across  the 
muscle  and  gapes  widely,  it  is  usually  unwise  to  sew^,  for  the 
sutures  will  cut  out  in  a  few  days  and  make  the  scar  much 
worse  than  if  it  had  been  left  alone.  An  ordinary  open  wound 
is  almost  certain  to  be  or  become  infected  even  after  washing  and 
disinfection ;  hence,  an  opening  should  usually  be  left  at  the 
bottom  for  drainage. 

Bandaging. — Occasionally  a  wound  is  such  that  the  edges 
can  be  held  together  by  means  of  bandages.  If  this  can  be  done, 
there  may  be  considerable  advantage  in  so  doing,  but  these 
wounds  are  rare.  Bandages  must  be  changed  frequently  and 
the  wound  kept  clean,  otherwise  much  more  harm  than  good 
results.  Provision  must  be  made  for  absorption  or  escape  of 
pus. 

Washing. — Few  of  these  wounds  are  much  benefited  by  wash- 
ing or  other  "home"  treatment.  If  a  wound  is  such  that  pus 
can  drain  from  it  freely  and  as  rapidly  as  formed,  there  is  little 
to  be  gained  by  ordinary  washing.  If,  on  the  contrary,  there 
are  deep  recesses  or  pockets  from  which  the  pus  cannot  drain, 
then  the  wound  must  be  so  altered  that  these  pockets  will  drain 


WOUNDS  93 

or  else  they  must  be  washed  out ;  otherwise  the  pus  may  burrow 
deeper. 

Carbolic  acid  and  similar  agents  are  commonly  used  so  dilute, 
as  to  be  without  any  effect  except -cleanliness.  When  used  strong 
enough  to  be  distinctly  antiseptic,  they  become  injurious  to  the 
wound  surface.  If  any  washing  is  necessary,  then  irrigate  freely 
with  warm  water  and  salt,  one  teaspoon  to  each  quart.  This  is 
efficient  and  not  injurious.  The  wound  surface  must  not  be 
rublied  during  the  process  of  cleansing. 

Dry  treatment. — Sometimes  quicker  and  better  results  can  be 
obtained  by  the  use  of  nonirritating  and  astringent  antiseptic 
powder;  for  instance,  the  following:  iodoform,  boracic  acid, 
and  tannic  acid,  in  equal  parts.  This  may  be  dusted  over  the 
surface  once  daily  to  produce  an  artificial  scab.  If  the  wound 
is  suppurating  freely,  it  may  be  advisable  to  irrigate  its  surface 
freely  for  fifteen  minutes  with  3  per  cent  creolin,  lysol,  or  car- 
bolic acid  in  water  before  applying  the  powder.  Use  the  powder 
freely.  In  some  cases  it  is  advisable  to  make  a  second  applica- 
tion of  the  powder  fifteen  minutes  after  the  first. 

If  the  suppuration  is  checked  and  the  surface  scabs  over,  then 
use  the  powder  only.  If  free  suppuration  begins  again,  repeat 
the  antiseptic  irrigation,  and  powder. 

Maggots. — This  trouble  can  usually  be  prevented  in  small 
wounds  by  smearing  the  following  mixture  around  the  border: 
turpentine  1  part,  tar  3  parts,  fish  oil  2  parts;  or,  powdered 
naphthalin  1  oz.,  lanolin  7  oz.  If  a  w^ound  becomes  infested 
with  maggots,  use  chloroform.  This  may  be  applied  either  by 
spraying  or  by  throwing  it  in  small  drops  from  a  sponge. 

Practical  suggestions. — Wounds  frequently  heal  more  rapidly 
and  perfectly  in  open  air  and  sunlight  than  in  the  stable,  be- 
cause there  is  more  ammonia  in  the  air  of  the  stable,  and  in- 
jurious germs  are  more  abundant.  Healing  of  some  wounds  is 
retarded  by  exercise,  and  such  patients  should  be  kept  in  the 
stable. 

Rest  from  motion  for  the  injured  parts  is  generally  favorable 
for  wound  healing. 

In  dressing  a  recent  wound,  all  dirt  and  foreign  material, 
and  usually  all  clots  of  blood,  should  be  carefully  removed.  This 
may  be  done  with  a  mild  antiseptic  solution  used  warm;  e.g., 
3  per  cent  carbolic  acid  or  3  per  cent  lysol,  or  the  plain  salt 
solution  referred  to  above.     Ordinary  surgeon's  absorbent  cot- 


94  VETERINARY  STUDIES 

ton  will  do  very  well,  but  there  should  be  no  unnecessary  rub- 
bing. 

Healing  wounds  vary  greatly  in  appearance.  The  wound  that 
is  called  "healthy"  or  that  is  doing  well  has  been  described 
under  "Healing  by  granulation."  "Wounds  that  are  "un- 
healthy" or  not  doing  well  may  be  either  pale,  or  dark  with 
considerable  heat,  or  show  large,  soft  and  dark  granulations 
(proud  flesh).  When  repair  has  apparently  ceased  and  there 
is  no  progi'css  toward  healing,  we  say  the  wound  is  indolent. 

The  so-called  proud  flesh  or  bad  granulation,  if  excessive, 
may  be  removed  from  "unhealthy"  wounds  by  the  knife  or  by 
cautery.  Inflamed  wounds  should  be  treated  with  repeated  long- 
continued  applications  of  the  weak  salt  solution  previously  men- 
tioned. 

Punctured  wounds,  e.g.,  nail  punctures  and  caulk  wounds  of 
the  feet,  are  especially  dangerous  on  account  of  liability  to  te- 
tanus (lock  jaw)  and  to  deep  formation  of  pus  with  absorption 
of  septic  poisons.  In  some  cases  they  should  be  opened  freely 
and  exposed  to  air,  which  greatly  reduces  the  danger.  The 
original  cleansing  and  disinfection  must  be  thorough  and  even 
radical.  The  ideal  way  is  to  make  such  a  wound  as  nearly  sterile 
as  possible,  and  as  soon  as  possible,  and  thereafter  keep  it  surgi- 
cally clean.     (See  Suggestions.) 

War  experience  on  a  very  large  scale  has  shown  the  great 
value  of  chlorin  preparations,  especially  hypochlorite  of  sodium 
as  perfected  in  Dakin's  solution,  for  lacerated  and  infected 
wounds.  Various  modifications  of  this  for  veterinary  use  are 
now  on  the  market,  and  promise  to  be  most  useful. 

Puncture  wounds,  like  nail  punctures  in  the  sole  of  the  foot, 
require  special  treatment  and  should  be  under  veterinary  care 
from  the  first  when  this  is  possible.  When  professional  help 
cannot  be  had,  then  for  the  nail  puncture,  enlarge  the  wound  in 
the  sole  and  treat  with  full  strength  Lugol's  solution  of  iodin  or 
with  tincture  of  iodin.  Then  pack  the  wound  with  cotton  soaked 
in  this  solution.  This  treatment  should  be  repeated  two  or  three 
times  the  first  day,  and  thereafter  the  wound  should  be  kept 
clean  and  provision  made  for  escape  or  absorption  and  removal 
of  any  discharge  that  may  develop. 

For  caulk  wounds  the  same  principle  applies.  But  in  these  it 
is  often  better  to  irrigate  for  half  an  hour  three  times  the  first 
day,  with  something  not  so  destructive,  e.g.,  2  per  cent  Lugol's 


WOUNDS  95 

or  even  the  normal  solution  of  common  salt,  mentioned  elsewhere 
in  this  chapter.  A  covering  of  sterile  cotton  and  bandage  should 
be  used.  Thereafter  avoid  infection.  If  reinfection  and  sup- 
puration should  occur,  then  cleaning  and  disinfection  must  be 
repeated. 

An  ordinary  fountain  syringe  or  some  similar  device  is  very 
satisfactory  for  continued  irrigation.  The  stockman  at  a  dis- 
tance from  veterinary  service  may  very  well  have  on  hand,  clean, 
sharp  and  ready,  a  few  instruments  for  emergencies,  e.g.,  two 
pairs  snap  artery  forceps,  cattle  trocar  and  cannula,  three  and 
a  half  inch  half  curved  needles,  milking  tubes,  castrating  knife 
and  metal  dose  syringe  for  giving  liquid  medicines. 

Failure  to  heal  may  be  due  to :  age  and  condition  of  general 
nutrition ;  kind  of  tissue  involved ;  impaired  blood  supply ;  to 
infection;  poor  treatment  and  especially  unwise  meddling. 

Do  not  rub,  w^ash,  bandage,  sew  or  meddle  in  any  way  except 
for  good  reason.  Given  a  healthy  animal  and  an  ordinary 
wound  that  drains  well,  the  stockman's  chief  duty  is  to  protect 
from  flies  and  dirt.  The  healing  will  then  usually  astonish  the 
owner.  Dirty  bandages  are  harmful;  fresh  air  and  sunlight 
are  very  helpful. 

As  a  matter  of  fact,  medicines  never  heal  a  wound.  The  tis- 
sue cells  do  all  the  healing  and  the  best  that  medicine  can  do  is 
to  give  the  cells  a  fair  chance.  The  best  medicine  that  can  come 
into  contact  Avith  a  clean  wound  surface  is  probably  clean  serum 
from  the  tissues. 


CAUSE  AND  PREVENTION 

LECTURE  XIX 
CONTAGIUM 

Any  living  virus,  either  plant  or  animal,  which  constitutes  the 
specific  and  primary  cause  of  disease,  and  which  may  be  trans- 
mitted from  one  animal  to  another  is  called  a  contagium  or  an 
infection.  An  outbreak  of  animal  disease  may  be  enzootic  (lo- 
cal), or  epizootic  (widely  spread). 

Description. — In  the  lower  forms  of  life,  bacteria  and  pro- 
tozoa, each  individual  consists  of  a  single  cell.  The  higher 
forms  such  as  molds,  are  larger  and  more  complicated.  Bac- 
teria molds,  etc.,  are  present  in  the  atmosphere  on  particles  of 
room  dust,  in  drinking  water,  in  the  soil,  and,  in  fact,  almost 
everywhere  in  great  abundance. 

Size. — Bacteria  (plants)  and  protozoa  (animal)  are  extremely 
small,  requiring  the  highest  powers  of  the  microscope  to  make 
them  distinctly  visible.  It  is  estimated  that  millions  may  live 
comfortably  in  a  single  drop  of  fluid.  Bacilli  vary  from  about 
1/25000  to  2/25000  of  an  inch  in  length.  Approximately  six 
red  blood  corpuscles  in  a  row^  would  fit  across  the  cut  end  of  a 
fine  hair,  and  about  six  ordinary  bacilli  in  a  row  would  reach 
across  one  corpuscle. 

Motion.— Some  of  these  forms  of  life  have  the  power  of  self- 
movement,  while  others  have  no  true  motility. 

Nutrition. — Bacteria  use  for  their  food  both  organic  and  in- 
organic food  materials  of  wide  variety.  Like  higher  beings,  they 
vary  in  their  likes  and  dislikes.  What  is  wholesome  for  one 
may  be  very  injurious  to  another.  Each  species  has  its  certain 
conditions  of  moisture,  temperature,  and  chemical  reaction  which 
are  most  favorable. 

Eeprodiiction. — These  little  beings  reproduce  by  fission  and 
by  spore  formation.  If  the  fission  is  incomplete,  they  remain 
in  chains.  The  spore  is  the  hardy  resistant  form  and  corre- 
sponds imperfectly  to  seed  formation  of  higher  plants.  It  is 
estimated  that  one  individual  may  increase  to  1,176,570  in  10 
hours. 

96 


CONTAGIUM  97 

Plagnes  in  history. — Throughout  all  the  pages  of  history,  we 
have  records  of  fearful  plagues  among  men  and  animals.  About 
fifteen  hundred  years  before  Christ  a  great  plague  of  animals 
swept  through  Egypt  and  made  a  great  slaughter  of  cattle.  We 
are  told  concerning  the  plague  at  Athens,  430  b.c,  that  dead 
men,  dead  animals,  and  dead  birds  lay  in  piles  on  the  streets, 
and  even  the  temple  floors  were  covered  with  bodies. 

Plagues  recurred  at  intervals  through  the  history  of  the  city  of 
Rome.  About  453  b.c.  an  outbreak,  possibly  anthrax,  destroyed 
nearly  one  half  the  population  of  Rome,  as  well  as  their  cattle, 
and  the  outbreak  spread  extensively  through  what  is  now  Italy. 
Cattle  plague  was  carried  into  England  in  1745,  with  heavy  loss. 
This  outbreak  lasted  for  several  years  in  various  parts  of 
Europe,  and  the  loss  cannot  be  estimated.  Within  present 
memory  have  come  several  enormously  expensive  outbreaks  oi 
hog  cholera  and  foot  and  mouth  disease.  Tuberculosis  has  long 
been  prevalent.  These  are  all  infectious  diseases  caused  by 
bacteria. 

The  above  are  but  isolated  examples  of  an  indefinite  number 
of  outbreaks  of  various  diseases  which  have  appeared  among 
domestic  animals. 

How  scattered. — Germs  of  diseases  are  scattered  by  a  very 
great  many  agencies;  for  instance,  the  germs  of  hog  cholera 
are  disseminated  by  means  of  sick  animals,  diseased  carcasses, 
hog  racks,  and  stock  cars,  and  they  may  be  easily  transferred 
by  the  shoes  or  clothing  of  persons  who  walk  through  an  in- 
fected yard.  Dogs,  and  possibly  birds,  serve  to  scatter  this 
disease  over  wide  areas.  Watering  troughs,  tanks,  ponds,  and 
sluggish  streams  are  all  common  sources  for  spreading  infectious 
diseases.  Infections  may  be  spread  in  any  ordinary  way  that 
very  fine  particles  of  dust  are  carried. 

Development  of  outbreaks. — It  seems  to  be  true  of  several 
diseases  tliat  the  germs  may  be  present  with  the  animal  or  his 
surroundings  but  are  not  virulent  enough  to  produce  disease. 
Under  favorable  conditions,  and  perhaps  after  passing  through 
the  bodies  of  several  susceptible  animals  in  succession,  they 
may  increase  sufficiently  in  virulence  to  produce  disease. 

Some  of  the  germs  producing  diseases  of  domestic  animals 
are  believed  to  live  for  very  long  periods  of  time  and  even 
vegetate  outside  the  animal  body,  possibly  in  the  soil  upon  or 
within  the  tissues  of  plants.     Some  germs,  especially  in  the  re- 


98  VETERINARY  STUDIES 

sisting  or  spore  stage,  may  live  for  very  long  periods  of  time, 
even  years,  and  under  very  unfavorable  conditions  retain  viru- 
lence, as  do  the  spores  of  anthrax  and  black-leg. 

Some  outbreaks  of  infectious  diseases  appear  very  suddenly, 
the  most  virulent  and  rapidly  fatal  cases  appearing  at  the  begin- 
ning. The  outbreak  then  gradually  loses  virulence,  the  last 
cases  being  of  a  decidedly  chronic  nature.  This  is  frequently  il- 
lustrated in  hog  cholera.  It  is  possible,  however,  that,  before  the 
virulent  form  was  noticed,  there  may  have  been  a  series  of  very 
mild  cases,  the  animals  not  being  appreciably  sick;  but  the 
germs,  in  passing  through  susceptible  bodies,  greatly  increased 
in  virulence  until  they  were  able  to  produce  a  rapidly  fatal  type 
of  the  disease. 

Body  entrance. — Germs  gain  entrance  with  the  inspired  air 
through  the  respiratory  organs;  through  the  digestive  organs; 
and  through  cuts  or  scratches  in  the  skin  and  mucous  mem- 
branes; and,  rarely,  infection  occurs  before  birth. 

Method  of  injury. — Germs  cause  injury  and  disease  in  at 
least  two  different  ways:  First,  by  rapid  multiplication  and 
mechanical  presence  in  inconceivable  numbers,  obstructing  the 
capillaries.  As  an  example  of  disease  caused  by  germs  in  this 
way,  at  least  partly  by  mechanical  presence,  we  have  anthrax 
and,  second,  more  common  and  serious,  germs  may  produce  in- 
tensely poisonous  substances  called  toxins,  in  the  blood  and 
body  tissue.  As  an  example  of  this  we  have  tetanus  and 
diphtheria. 

One  class  of  bacterial  toxins  are  apparently  liberated  in  the 
body  fluid,  as  produced  in  tetanus  (lockjaw).  Another  class 
of  bacterial  poisons  are  held  in  the  bodies  of  bacteria  producing 
them  until  the  bacterial  cell  is  destroyed,  as  in  glanders.  These 
poisons  injure  or  kill  in  various  ways  just  as  do  other  chemical 
poisons,  tetanus  toxin,  for  instance,  which  causes  excessive  stim- 
ulation of  muscle  fibers.  Others  cause  fatal  depression  of  vital 
organs  as  in  human  diphtheria. 

Often  several  species  of  bacteria  cooperate  in  producing  the 
original  disease,  as  in  hog  cholera  or  the  pus  pockets  of  actino- 
mycosis. There  may  occur  a  secondary  invasion  by  a  different 
species.  The  second  invader  may  add  to  the  seriousness  and 
even  change  the  features  of  the  disease  although  it  may  be  in- 
capable of  causing  the  original  disease  alone.  This  condition  is 
common  in  tuberculosis  and  hog  cholera. 


CONTAGIUM  99 

Resistance. — The  body  resists  bacterial  invasion  and  injury 
in  various  ways.  Fever  which  follows  many  infections  gives  a 
temperature  which  is  unfavorable  to  the  invading  bacteria  and 
which  otherwise  opposes  the  invasion.  The  white  blood  cells, 
aided  by  natural  substances  in  the  plasma,  destroy  bacteria. 
Gland  secretions,  such  as  gastric  juice,  are  destructive.  Vari- 
ous antagonistic  substances  are  naturally  present  in  the  blood 
and  are  hurriedly  increased  when  bacterial  invasion  occurs.  In 
response  to  the  toxin,  the  body  produces  antitoxin,  as  in  tetanus 
or  human  diphtheria.  Substances  (bacteriolysins)  are  produced 
which  dissolve  and  destroy  the  invading  bacteria.  In  various 
ways,  then,  the  body  tries  to  check  or  destroy  the  bacteria  and 
neutralize  their  poisons.  These  ^  rr\rr  Arp-An. 
factors  together  constitute  im-       •  COCGACEA& 


'e^ 


munity,  which  is,  of  course,  of        

all  degrees  of  extent  and  dura-       MBB  BACT&RIACE'AE: 
tion. 

Nature    disposes    of    disease        ""^    SPIRILLACtAE'  TYP&5 
germs   in   a  variety   of   ways,        X-^n^^*-^_^.„- 
principally    by    oxidation,    by      ^^^   36._a,,.ERAL  Groups  of  Bac- 
the  devitalizing  effect  of  sun-       teria.  Diagrammatic.   (M.  H.  E.) 
light,  by  scattering  them  over 

wide   areas   and   by   enormously   diluting   them   by   wnnd   and 
water. 

Classification. — There  are  three  general  family  types  of  bac- 
teria : — 

Coccaceoe. — These  are  spherical.  A  great  many  of  the  most 
common  diseases  are  caused  by  germs  w-hich  belong  to  this  gen- 
eral family;  for  instance,  erysipelas  and  various  types  of  blood 
poisoning,  abscesses  and  sloughing. 

Bacteriacecf. — These  are  rod-shaped  germs.  Among  the  com- 
mon diseases  of  live  stock  which  are  caused  by  germs  belonging 
to  this  general  family  are  tuberculosis,  glanders,  tetanus  (lock- 
jaw), and  hemorrhagic  septicaemia. 

Spirillacexe. — The  individuals  are  rod-shaped,  curved,  or  spiral 
and  may  be  short  or  long.  The  specific  cause  of  Asiatic  fever 
(human)  belongs  in  this  general  group.  Either  tyi)e  may  show 
the  isolated  individual  or  groui)s  adherent  in  chains. 

Filterable  virtus. — We  have  also  a  little  understood  group  of 
filterable  and  invisible  viruses,  i.e.  viruses  which  are  so  small 
that  they  pass  through  laboratory  filters  and  are  invisible  under 


100  VETERINARY  STUDIES 

present  day  microscopes.    Several  important  diseases  like  pleuro- 
pneumonia and  hog  cholera  are  caused  by  filterable  viruses. 

Protozoa. — Protozoa,  minute  one-cell  animal  microorganisms, 
are  now  recognized  as  the  cause  of  such  serious  diseases  as 
dourine,  a  venereal  disease  of  horses,  and  syphilis  and  malaria 
of  the  human. 

Practical  suggestions. — The  student  should  bear  clearly  in 
mind  that  bacteria  or  germs  usually  require  very  favorable  con- 
ditions for  existence,  and  especially,  for  retaining  disease-pro- 
ducing power.  Sunshine  and  ventilation,  vigorous  health,  and 
high  resisting  power  of  an  animal,  are  unfavorable  to  the  pres- 
ence and  activity  of  any  contagium.  Any  factor  which  increases 
animal  resistance  or  decreases  the  virulence  of  an  infection,  is  a 
protection  against  infectious  disease. 

Disease  germs  are  actual  substances,  tiny  particles  of  living 
matter,  which  may  be  carried  about  in  any  way  that  any  very 
fine  particles  of  heavy  dust  may  be  scattered. 

The  beginning  of  an  outbreak  may  come  in  two  ways:  by 
recent  introduction  of  germs,  for  example  anthrax  in  northern 
states ;  or  it  may  apparently  be  caused  by  increased  virulence  in 
germs  already  present,  but  not  previously  capable  of  producing 
disease.  Such  an  increase  of  virulence  may  be  due  to  surround- 
ing conditions,  which  especially  favor  germ  life,  or  to  prelimi- 
nary passage  through  an  animal  of  very  low  resistance.  This 
probably  occurs  in  pneumonia. 

Apparently  the  number  of  germs  taken  into  the  body  makes 
a  difference  in  the  severity  of  some  diseases — hence  the  necessity 
of  sunshine  to  reduce  virulence  and  destroy  germs  and  of  venti- 
lation to  carry  as  many  germs  as  possible  out  of  the  stable. 

Bearing  in  mind  now  what  has  been  said  of  germs,  it  is  easy 
to  see  how  glanders,  with  infection  left  in  feed  boxes  or  water 
pails,  may  be  spread  from  horse  to  horse ;  how  hog  cholera  with 
its  infection,  especially  in  the  manure  or  carcass,  may  be  easily 
and  rapidly  spread;  or  how  lumpy  jaw  may  be  spread  by  germs 
in  the  pus  scattered  from  abscesses. 

Infectious  diseases  do  not  "just  happen"  any  more  than  mus- 
tard just  happens  in  a  wheat  field.  In  both  cases  alike  there 
must  be  definite  planting  of  seed  and  favorable  conditions  for 
its  growth.  Spore  formation  on  the  part  of  certain  bacilli, 
anthrax  for  example,  is  much  more  than  a  scientific  phenome- 
non.     A    pasture   which    remains   contaminated   with    anthrax 


CONTAGIUM  101 

spores  for  many  years  means  life  or  death  to  animals  and 
lK'0])le. 

Susceptibility  and  immunity  are  only  relative  terms,  and  they 
vary  within  wide  limits.  They  depend  on  many  factors :  the 
species  of  animals,  age,  exposure,  fatigue,  previous  disease, 
heredity,  etc.  An  animal  naturally  immune  to  a  certain  germ 
may  contract  infection  when  greatly  fatigued. 

Immunity  may  be  natural  or  acquired.  Natural  immunity 
may  be  racial  or  individual ;  to  illustrate,  the  human  resists 
hog  cholera,  and  the  hog  resists  measles  and  smallpox.  Indi- 
viduals of  the  same  species  may  differ  widely  in  power  of  resis- 
tance. In  an  outbreak  of  cholera  in  previously  unexposed  herds, 
there  are  usually  individuals  that  never  miss  a  feed.  Acquired 
immunity  is  passive  where  one  animal  receives  its  immunizing 
substances  from  another,  as  in  serum — only  treatment  for  hog 
cholera.  It  is  active  when  an  animal  is  exposed  to  living  virus, 
either  by  natural  or  artificial  process,  and  survives;  thereafter 
providing  its  own  inununizing  substance.  Passive  immunity  is 
temporary;  active  immunity  is  relatively  permanent,  as  in  the 
serum-virus  treatment  for  hog  cholera  or  reduced  virulence, 
virus  is  used  to  vaccinate  calves  against  blackleg. 


LECTURE  XX 
DISINFECTION 

Purpose. — In  veterinary  practice,  disinfection  is  intended  to 
check  the  spread  of  infectious  diseases,  and  to  protect  animals 
already  diseased  from  further  infection,  by  killing  the  causative 
microorganisms  or  by  rendering  them  avirulent. 

Sources  of  infection. — In  any  process  of  disinfection  it  is 
important  to  know  the  nature  of  the  infecting  germ  and  the 
sources  from  which  it  comes.  Germs  of  diseases  are  spread  in 
many  ways;  for  instance  by  the  manure  or  body  fluids  of  sick 
animals,  by  soiled  water  or  food,  or  by  any  other  contaminated 
matter.  Air  may  be  contaminated  from  the  skin  or  lungs  of 
diseased  animals,  for  example  by  the  coughing  of  a  tuberculous 
cow.  The  soil  may  be  contaminated  by  the  burial  of  diseased 
animals  or  by  the  deposit  of  any  infectious  material  upon  the 
surface.  In  such  case,  germs  may  be  washed  to  ponds,  sluggish 
streams,  or  shallow  wells,  contaminating  the  water.  Hides, 
offal,  and  even  the  hair  of  a  diseased  animal,  may  be  the  means 
of  spreading  disease,  as  in  case  of  animals  which  have  died  of 
anthrax. 

Diseases  are  often  spread  by  ' '  carriers, ' '  for  example,  glanders 
of  horses  or  tuberculosis  of  cattle,  i.e.,  by  an  animal  which  does 
not  show  the  disease. 

Thoroughness. — Disinfection  is  not  reliable  and  should  not  be 
depended  upon  unless  done  most  thoroughly.  To  illustrate,  a 
stable  must  first  be  thoroughly  cleaned  of  manure,  litter  and 
cobwebs.  Scrubbing  is  often  necessary  before  the  disinfectant 
can  be  effectively  applied.  A  small  yard  may  be  disinfected  by 
burning  straw  on  it,  or  by  removing  the  earth  to  a  depth  of  at 
least  six  inches  and  replacing  it  with  fresh  earth.  Paved  floor- 
ing may  be  disinfected  by  burning  over  it  any  inflammable  ma- 
terial. Cracks  should  be  disinfected  by  the  free  use  of  corrosive 
sublimate  solution.  Food  which  may  have  been  contaminated 
should  ordinarily  be  destroyed,  but  in  some  cases  it  may  be 
given  to  nonsusceptible  animals.     Drinking  places,  currycombs, 

102 


DISINFECTION  103 

brushes  and  all  such  articles  should  be  disinfected.  Dogs,  rats, 
and  any  of  the  smaller  animals  which  are  liable  to  convey  the 
disease  should  be  guarded  against. 

A  pail  spray  pump  is  satisfactory  for  the  small  job ;  whereas 
a  barrel  spray  pump  is  more  practical  for  a  larger  job.  About 
fifteen  feet  of  hose  is  usually  needed  with  a  piece  of  metal  pipe 
several  feet  long  at  the  nozzle  end.  It  pays  well  to  strain  very 
carefully  if  lime  or  any  sedimenting  material  is  used. 

Attendants. — Attendants  on  sick  animals  should  be  most  care- 
ful about  their  clothing,  particularly  trousers  and  shoes.  It  is 
well  to  use  special  overalls  and  overshoes,  and  leave  them  in  the 
infected  stall  or  l)uilding. 

Burning  a  caxcass. — A  cross-shaped  trench  about  twelve 
inches  deep  in  the  center,  and  shallow  tow^ard  the  edges,  about 
seven  feet  long  each  way,  is  dug  in  the  ground.  The  earth  is 
thrown  in  the  angles,  two  bars  of  iron  are  placed  across  for  a 
bridge  and  the  fuel  placed  upon  the  bars.  The  trunk  of  the 
carcass  is  placed  upon  the  fuel,  another  layer  of  fuel  is  added, 
then  the  internal  organs  and  limbs,  and  finally  another  layer  of 
fuel.  The  cross-shaped  trench  provides  a  draft — regardless  of 
the  direction  of  the  wind.  Cheap  fuel  oil  may  prove  a  great 
help,  especially  for  cattle. 

Disinfectants 

Carbolic  acid. — Pure  carbolic  acid  is  usually  seen  in  the  form 
of  light-colored  crystals,  sometimes  slightly  red.  As  sold  in  the 
drug  stores,  it  is  usually  liquefied  by  the  addition  of  5  to  8  per 
cent  of  water.  It  is  soluble  in  water  up  to  about  6  per  cent.  It 
is  objectionable  because  it  is  very  poisonous,  and  is  not  reliable 
for  some  infections,  hog  cholera  for  instance.  It  does  not  de- 
stroy clothing  or  corrode  metals  as  corrosive  sublimate  does  how- 
ever. The  best  antidote  for  internal  poisoning  or  external  burns 
by  carbolic  acid  is  probably  alcohol,  which  may  be  given  in 
large  doses  for  this  purpose.  For  general  disinfection  use  car- 
bolic acid  as  a  5  per  cent  solution. 

Lysol. — Lysol  has  about  the  same  qualifications  as  creolin  and 
compound  cresol  and  acts  in  a  similar  manner. 

Compound  cresol. — Compound  cresol  (Liq.  Comp.  Cresol), 
is  a  dark  l)rown  li(|uid,  consisting  of  cresol  and  linseed  oil  soap, 
a  standard  formula,  and  can  be  prepared  by  any  druggist.     It 


104  VETERINARY  STUDIES 

mixes  well  with  soft  water,  and  fairly  well  with  ordinary  water. 
This  is  used  in  2  to  3  per  cent  solution  or  about  4  ounces  per 
gallon.  It  is  much  cheaper  and  more  efficient  than  carbolic 
acid  and  a  thoroughly  reliable  and  useful  disinfectant. 

Proprietaiy  coal  tax  products. — There  is  a  long  list  of  coal 
tar  products.  They  are  similar  to  compound  cresol,  and  are 
usually  reliable  when  approved  by  the  federal  Bureau  of  Animal 
Industry  and  used  in  the  approved  strength. 

Formalin. — Formalin  is  a  very  important  disinfectant,  either 
as  a  liquid  or  vapor.  It  is  active  and  reliable,  when  properly 
used  and  does  not  injure  paint  or  metals.  It  is  in  the  market 
as  a  40  per  cent  solution  of  formaldehyd  gas.  The  odor  is  irri- 
tating and  disagreeable,  somewhat  resembling  chlorin.  Forma- 
lin is  apparently  more  active  in  the  presence  of  moisture.  For 
use  in  vapor  form,  at  least  20  ounces  per  1000  cubic  feet  should 
be  introduced  rapidly  into  a  tight  room. 

Formalin  may  be  vaporized  very  satisfactorily  by  combination 
with  permanganate  of  potash  in  powder  or  fine  crystals,  in  the 
proportion  of  16  ounces  of  jDermanganate  and  20  ounces  forma- 
lin for  each  1000  cubic  feet  of  air  when  the  inside  temperature 
is  65  degrees  F.  or  above.  Use  one  fourth  to  one  half  more  of 
the  disinfectants  for  lower  temperatures.  A  large  flaring  tin 
pail  is  used  for  each  such  mixture.  The  permanganate  sJiovId 
he  put  in  first. 

The  building  must  be  made  tight.  Strips  of  wet  newspaper 
do  very  well  for  cracks  and  small  holes.  Leave  the  building 
closed  for  at  least  six  hours,  with  no  inflammable  material  in 
the  room  close  to  the  outfit.  This  method  is  applicable  only  to 
small  tight  buildings.    At  low  temperatures,  it  is  unreliable. 

Heat. — Fire  is  the  most  reliable  disinfectant,  and  the  one  that 
should  invariably  be  used  where  an  article  is  to  be  destroyed. 
Moist  heat  is  more  active  and  reliable  than  dry  heat  at  the  same 
temperature.  Boiling  for  an  hour  is  probably  sufficient  to  de- 
stroy or  render  harmless  any  known  disease  producing  germs. 

Corrosive  sublimate. — This  is  sold  in  the  form  of  white  crys- 
tals or  powder.  It  dissolves  in  about  16  parts  of  water,  and  its 
solubility  ^can  be  increased  by  muratic  acid  or  iodide  of  potash. 
It  is  disinfectant  in  the  proportion  of  1  to  2000,  about  Si/o  grains 
to  a  pint  of  water,  and  in  even  more  dilute  solution.  A  con- 
venient solution  can  be  made  by  dissolving  it  in  alcohol,  1  to  8. 
A  teaspoonful  of  this  to  a  quart  of  water  gives  about  1  to  2000 


DISINFECTION  105 

solution.  Corrosive  sublimate  is  very  cheap  and  reliable ;  but  it 
is  poisonous,  it  coagulates  albumin,  and  corrodes  and  destroys 
metals.     However  it  is  a  very  practical  disinfectant. 

Sulphur. — Probably  suljiliur  is  not  as  elBcient  a  disinfectant 
as  it  is  generally  supposed  to  be,  although  a  large  quantity  of  it 
seems  to  have  decided  germ  destroying  properties  when  it  is 
used  after  the  surfaces  to  be  disinfected  have  been  moistened  by 
steam  or  otherwise,  and  when  the  doors  and  windows  are  kept 
tightly  closed  for  a  long  period  of  time  afterward.  About  10 
pounds  per  1000  cubic  feet  of  air  is  needed.  It  is  easily  burned 
if  three  or  four  ounces  of  alcohol  are  added.  The  mixture  should 
be  placed  in  an  iron  kettle  and  the  kettle  placed  in  a  tub  of 
boiling  water,  partly  for  safety  and  partly  for  moisture. 

Sunshine. — Sunshine  destroys  germs.  Long  exposure  to  sun- 
shine, where  time  permits,  will  render  safe,  infected  clothing  or 
any  other  article  carrying  an  infection  on  its  surface. 

Lime. — Used  in  the  form  of  fresh  whitewash  lime  is  very  use- 
ful as  a  disinfectant  for  many  places.  It  is  improved  in  reli- 
ability by  ^  to  1/2  pound  fresh  chlorid  of  lime  to  the  gallon. 
For  use  by  spray  pump,  it  must  be  rather  thin  and  well  strained. 
Slake  by  adding  1  pint  water  to  2  pounds  fresh  stone  lime. 

Milk  of  lime  is  prepared  by  adding  water  to  the  slaked  lime 
4  to  1  by  volume.    Whitewash  is  merely  thinned  milk  of  lime. 


LECTURE  XXI 
HEREDITY— AIR 

Heredity  is  the  great  law  of  inheritance  that  "like  tends  to 
produce  like."  This  tendency  may  apply  to  any  peculiarity. 
Heredity  may  appear  as  a  factor  in  the  cause  of  disease  when 
actual  disease  germs  are  transmitted,  which  is  rare,  or  when  a 
local  weakness— an  ill  shaped  hoof  and  sidebone,  for  example — 
or  general  susceptibility  appears  which  is  favorable  to  the  de- 
velopment of  disease— for  example,  a  very  low  resistance  to  hog 
cholera.  It  should  be  borne  in  mind  that  susceptibility  and 
immunity  are  but  varying  degrees  of  the  same  thing.  Statistics 
are  meager,  but  essential  facts  are  very  plain  as  to  the  relation 
of  heredity  to  many  diseases.  Young  pigs  from  an  immune  sow 
are  frequently  born  with  considerable  immunity;  but  most  of 
them  gradually  lose  this  inherited  immunity  as  they  grow 
older. 

Theory. — The  modern  idea  of  heredity  in  relation  to  disease 
is  that  the  thing  actually  inherited  is  usually  only  a  tendency 
or  a  lessened  resistance.  This  may  refer  to  the  white  corpuscles 
and  serum  of  the  blood  as  well  as  to  the  muscle  and  tendon  or 
bone  cells.  This  theory  of  lessened  resistance  applies  to  such 
conditions  as  spavins,  ringbones,  sidebones,  roaring,  and  internal, 
diseases  alike.  Under  favorable  conditions  the  actual  develop- 
ment of  disease  may  not  occur.  A  stallion  with  certain  defects 
of  the  eyes  is  apt  to  sire  colts  with  bad  eyes.  ]\Iares  with  curby 
or  spavined  hocks  are  equally  apt  to  raise  colts  with  bad  hocks. 
In  rare  cases  the  young  is  born  with  the  actual  disease  present. 

In-and-in  breeding-. — This  tends  in  some  cases  toward  decrease 
of  physical  vigor,  infertility,  tendency  to  abortion,  and  various 
other  diseases,  especially  when  long  continued  and  with  unwise 
mating. 

Am 

Air  is  a  very  frequent  source  of  disease.  Its  composition  in  a 
general   way  is:   oxygen   1-5,   nitrogen,   4-5;   more  accurately, 

106 


HEREDITY— AIR  107 

oxygen  20.97  per  cent,  nitrogen  79  per  cent,  and  carbon  dioxid 
gas  (CO2)  .03  per  cent. 

Impurities  in  air  are  taken  care  of  by  nature  througli  dif- 
fusion, oxidation,  sunlight,  and  plant  life  activity.  Common 
impurities  in  air  are  carbonic  gas,  ammonia,  and  bacteria  of 
many  different  kinds;  scales  and  debris  of  epithelium,  hair, 
sputum,  dried  manure,  dried  pus,  etc. 

Belation  to  disease. — Diseases  related  to  impure  air  are  many 
and  serious. 

Horses'  lungs  have  about  289  square  feet  of  air-absorbing 
surface  or  five  times  the  skin  area.  They  may  contain  at  one 
time  1.5  cubic  feet  of  air.  Horses  at  rest  may  give  off  6.5  to 
7.5  cubic  feet  of  COo  every  hour. 

Air  begins  to  get  foul  when  oxygen  is  reduced  to  20.6  per 
cent,  or  when  CO2  goes  above  .05  per  cent;  neither  is  neces- 
sarily harmful,  however. 

Carbon  dioxid  (CO2)  is  not  of  itself  poisonous  in  small  quan- 
tities but  it  is  significant  because  of  impurities  with  which  it 
may  be  associated.  Common  statements  that  COo  at  1  per  cent 
is  very  poisonous  or  fatal  are  nonsense.^  When  present  in  very 
great  excess,  it  supplants  oxygen,  causes  paralysis  of  heart,  and 
overwork,  then  failure  of  the  lungs,  and,  finally,  oxygen  star- 
vation. 

Hydrogen  sulphide  may  also  be  present  in  the  air.  A  very 
small  amount  is  said  to  be  fatal  to  horses,  causing  diarrhea  and 
extreme  weakness. 

Nitrogen  is  nearly  negative  in  effect.  It  merely  dilutes  oxy- 
gen and  CO,. 

Ammonia  in  air  must  also  be  regarded  as  an  impurity,  so  far 
as  animal  life  is  concerned,  mainly  because  of  the  organic  mat- 
ters with  which  it  associates,  and  because  of  its  irritating  eft'ect 
upon  the  res]nratory  organs. 

Practical  application. — A  very  practical  lesson  and  a  very 
obvious  one  is  breed  from  sound  and  vigorous  stock.  Farmers 
who  patronize  unsound  and  inferior  sires  simply  because  the  cost 
of  service  is  low  are  unwise.  The  Minnesota  stallion  law  speci- 
fies infectious  diseases,  and  also  the  follo^nng  diseases,  as  bars 
for  registration  on  the  ground  that  they  are  transmissible  either 
directly  or  indirectly  by  heredity;  bone  spavin,  ringbone,  side- 
bone,  and  curb  when  accompanied  by  curby  hock. 

"■  See  Minn.  Exp.  Sta.  Bulletin  98. 


108  VETERINARY  STUDIES 

Farmers  should  not  patronize  stallions  affected  with  any  of 
these  conditions,  nor  shonld  they  be  misled  into  purchasing  such 
stallions.  The  present  outlook  is  that  such  stallions  will  be 
barred  from  public  service  in  a  large  number  of  states  within  a 
few  years.  It  should  be  borne  in  mind  that  a  fat  animal  is  not 
necessarily  sound  or  healthy.  Domestic  animals  may  be,  and 
frequently  are,  in  show  condition,  and  yet  badly  diseased.  A 
show  bull  may  be  rotten  with  tuberculosis ;  a  handsome  stallion 
may  be  very  unsound.  Tuberculous  cows  have  broken  milk 
records. 

The  spread  of  tuberculosis  in  a  stable  is  a  good  illustration 
of  transmission  of  disease  due  to  bad  air  conditions.  With  an 
infectious  case  of  tuberculosis  already  in  the  herd,  tuberculosis 
spreads  much  more  rapidly  in  unventilated  stables  than  in  well- 
ventilated  stables.  Bacteria  tend  to  adhere  to  whatever  they 
may  fall  upon  and  do  not  Hoat  in  air,  except  as  carried  on  dust 
or  other  particles.  Hence,  stable  dust  becomes  an  important 
factor  in  disseminating  disease.  But  it  should  be  remembered 
that  bacteria  differ  widely  in  ability  to  withstand  drying.  Most 
of  them  do  not  long  remain  alive  and  virulent  in  contact  with 
dry  dust,  or  dry  surfaces  in  a  dry  atmosphere. 

Ventilation  is  very  important  and  should  be  thorough.  It 
accomplishes  several  purposes:  it  admits  oxygen,  dilutes,  re- 
moves impurities,  controls  moisture  and  gives  the  required  air 
movement.  Good  ventilation  implies  rapid  change  in  air  with- 
out direct  draughts  upon  confined  animals.  Each  mature  cow 
or  horse  should  have  about  35  square  feet  of  floor  space  and  at 
least  500  cubic  feet  of  air  space,  and  the  air  should  be  renewed 

frequently. 
Sunshine  is  even  more  important,  for  sunshine  is  nature's 

universal  disinfectant,  killing  germs  of  disease.     Windows  and 

stable  frontage  should  permit  of  a  sweep  of  sunlight  over  the 

largest  possible  surface  of  floors  and  fixtures. 


LECTURE  XXII 
VENTILATION 

Purposes. — There  are  several  purposes  in  ventilation ;  viz., 
getting  fresh  air  with  its  oxygen  into  a  stable,  getting  impuri- 
ties of  various  kinds  out  of  the  stable,  regulating  temperature, 
and  controlling  moisture. 

Impurities. — The  common  impurities  of  air  are :  disease  germs 
and  their  products,  dust,  carbon  dioxid  and  other  gases.  Ex- 
cess heat  and  moisture  in  a  stable,  while  not  impurities,  are  very 
objectionable. 

Stable  air.— One  good  authority  (F.  Smith)  reports  analyses 
of  air  for  European  stables.    These  are,  of  course,  variable,  but 


Fig.  37. — Ventilation.     {Paige.) 

Outlet  witli  too  many  angles.  Cow  receiving  inlet  air  from  over  a 

manure  pile. 

Smith's  figures  give  a  good  general  statement.  The  average  of 
28  analyses  gave  .14  per  cent  carbonic  gas  (CO,).  In  another 
series  of  28  analyses  he  found  an  average  of  .21  per  cent.  In 
recent  American  work,  Clarkson  and  Smith  found  .25  per  cent 
CO2  as  an  average  of  6  tests  in  a  well  ventilated  stable.  In  an- 
other stable  witli  still  better  ventilation,  they  found  .14  per  cent 
as  the  average  of  6  tests.    For  a  normal  outside  air  we  may  take 

about  .03  per  cent  CO^. 

109 


110  VETERINARY  STUDIES 

In  some  of  our  own  work  (Reynolds  and  Lipp)  with  a  steer 
closely  confined  in  specially  prepared  tight  stall,  we  obtained 
the  following  record  of  CO,  percentages  after  varying  periods 
of  confinement.  After  6  hours,  .94  per  cent;  after  12  hours, 
.71  per  cent;  average  after  two  24-hour  periods,  1.03  per  cent; 
after  48  hours,  .68  per  cent.  The  animal  was  a  young  steer 
weighing  about  500  pounds,  and  was  confined  in  a  stall  contain- 
ing 784  cubic  feet  of  air. 

Another  steer  200  pounds  heavier  in  the  same  series  of  experi- 
ments gave  for  an  average  of  three  24-hour  periods,  1.09  per 
cent;  at  42  hours,  .98  per  cent.  It  may  be  interesting  for  the 
student  to  note  the  decrease  of  CO2  rather  than  an  increase, 
which  would  usually  be  expected.  This  occurred  many  times  in 
our  experimental  work  and  is  quite  easily  explained  on  chemi- 
cal grounds. 

Necessity  of  ventilation. — To  illustrate  the  effect  of  poor 
sanitary  conditions,  particularly  lack  of  ventilation,  it  is  only 
necessary  to  call  attention  to  the  common  experience  of  moving 
an  animal  affected  with  chronic  glanders  or  tuberculosis  from 
a  well-lighted  and  well-ventilated  stable  to  one  where  the  con- 
ditions are  the  opposite.  Under  the  latter  conditions  there 
is  often  rapid  development  of  a  disease  which  had  been 
mild. 

Sick  animals,  especially  those  affected  with  respiratory  diseases 
— and  this  is  true  of  many  other  diseases — need  free  ventilation. 

A  warmly  constructed  barn  in  a  cold  climate  is  desirable  if 
sanitary  conditions,  such  as  abundant  air,  sunlight,  good  food, 
and  water,  are  provided.  A  good  barn,  with  good  ventilation, 
should  maintain  a  temperature  above  freezing  even  in  very 
cold  weather.  This  means  warm  construction — number  and  kind 
of  animals  taken  into  consideration.  But  making  a  barn  warm 
and  tight  may  very  easily  establish  an  ideal  place  for  the  propa- 
gation of  germs,  the  spread  of  disease,  and  lowering  of  animal 
vigor. 

Carbonic  gas  (CO,)  can  no  longer  be  considered  a  reliable 
index  of  an  atmosphere's  injurious  quality.  In  fact,  our  work 
has  shown  it  to  be  a  very  unreliable  guide  in  this  respect.  But 
it  is  a  convenient  guide  as  to  the  amount  of  ventilation  accom- 
plished. 

Unventilated  stable  air. — Writers  and  teachers  on  the  subject 
of  hygiene  are  agreed  that  unventilated  air  is  harmful.     The 


VENTILATION  111 

student  may  safely  take  their  statements  as  correct  in  a  general 
Avay,  but  may  just  as  safely  doubt  the  usual  explanation. 

Work  done  at  the  Minnesota  Experiment  Station  seems  to 
demonstrate  quite  conclusively  that  the  accepted  explanations 
are  incorrect;  that  any  probable  increase  of  CO2  or  any  prob- 
able decrease  of  oxyg-en  are  not  especially  important.  This 
work  seems  to  show  that  the  injury  comes  from  entirely  dif- 
ferent factors. 

The  :\linnesota  Station  has  had  a  number  of  different  animals 
continue  apparently  in  good  health  when  confined  for  consid- 
erable periods  in  very  high  percentages  of  COo.  In  one  case  a 
steer  made  good  gains,  was  bright  and  active,  and  showed  no 
important  physiological  disturbances  when  long  confined  in  air 
containing  COo,  ranging  as  high  as  2.67  per  cent,  or  nearly  90 
times  the  average  for  outside  air. 

Experimental  work  shows  that  decrease  of  oxygen  does  not 
lessen  the  amount  absorbed  by  the  animal  until  we  reach  the 
very  low  level  of  about  13  per  cent,  20.97  per  cent  being  taken 
as  a  normal.  But  13  volumes  per  cent  is  much  lower  than  would 
be  found  in  any  stable. 

Excretion  of  CO,  may  be  checked  and  difficult  respiration 
occur  in  case  of  very  great  excess  of  this  gas.  It  has  been 
found  by  other  experimenters  that  when  the  air  contains  from 
3  to  4  volumes  per  cent  of  CO.  the  excretion  of  gas  might  be 
checked  50  per  cent,  with  no  harmful  effect  detected.  The  ex- 
cretion of  CO2  is  practically  independent  of  percentage  of 
oxygen  in  the  air.  One  very  good  authority  tells  us  that  tissue 
metabolism  is  not  disturbed  by  variation  of  oxygen  above  10.5. 
Below  10.5  percentage  of  oxygen  there  were  marked  physiologi- 
cal disturbances;  but  this  is  far  below  any  probable  stable  per- 
centage. 

There  does  not  appear  to  be  any  good  reason  for  doubting 
the  importance  of  stable  ventilation.  It  is  equally  plain,  how- 
ever, that  the  injurious  effects  of  unventilated  air  in  common 
stables  does  not  come  from  high  COo  or  low  oxygen  percentages, 
and  that  we  must  seek  the  explanation  in  other  directions. 

Accumulation  of  liarmful  germs  gives  a  portion  of  the  ex- 
planation. Modern  research  shows  that  11i<'  physical  condition 
of  the  air,  rather  than  the  chemical  composition,  is  the  impor- 
tant factor.  Aside  from  bacterial  content  of  the  air  and  irri- 
tating substances,  the  important  thing  in  ventilation  is  the  con- 


112 


VETERINARY  STUDIES 


trol  of  temperature  and  moisture.  Mere  motion,  aside  from  its 
relation  to  other  factors,  has  not  been  shown  to  be  important 
for  stock. 

Natural  forces. — The  factors  that  operate  in  natural  ventila- 
tion are :  the  force  of  the  wind ;  the  weight  of  air,  as  varied  by 
its  temperature ;  the  diffusion  of  gases  in  obedience  to  a  natural 
law;  and  the  force  of  the  wind  is  probably  the  most  important 
one  of  these  factors,  and  must  always  be  taken  into  considera- 
tion in  planning  ventilation  or  in  making  mathematical  esti- 
mates of  the  amount  of  air  needed.  The  force  of  the  wind  is, 
of  course,  irregular ;  but  variations  can  be  made  in  the  ventilat- 


//y/>'^^ 


Fig.  38. — Ventilation.     (Paige.) 
Air  Currents.  Manger  front  inlet. 


ing  facilities  to  compensate  for  this.  The  incoming  air  should 
not  pass  over,  or  through,  any  contaminating  source,  such  as 
a  manure  pile,  and  it  is  very  important  that  the  general  plan  of 
construction  should  be  well  considered. 

Temperature  and  weight.— The  second  factor,  difference  in 
weight  between  the  lighter  warm  and  heavier  cold  air,  is  not 
so  important  in  natural  (windows  and  doors)  as  in  artificial 
ventilation,  and  yet  it  is  a  factor  of  considerable  importance. 
The  heat  which  warms  the  air  in  the  lower  levels  is  that 
which  comes  from  the  bodies  of  the  confined  animals,  as  it  is 
radiated  from  the  surface  or  warmed  in  passing  through  the 

lungs. 

Diffxision  of  ^as^es.— Carbonic  gas  is  considerably  heavier  than 
air,  but  the  lower  air  levels  usually  do  not  usually  show  much 
more  CO2  than  the  higher  ones  on  account  of  diffusion,  which 
takes  place  in  response  to  the  law  of  diffusion  of  gases — operat- 
ing independently  of  relative  weights.     This  force  is  so  strong 


VENTILATION  113 

in  its  action  that  considerable  diffusion  takes  place  through  lum- 
ber and  ordinary  brick,  and  other  building  materials. 

Air  Currents 

An  entering  current  of  air  has  the  effect  of  inducing  other 
currents  within  the  stable,  tlie  induced  currents  setting  in  at 
right  angles  to  the  inlet  current. 

With  AvhidoAVs  wide  open  to  windward,  and  openings  on  the 
other  side  of  the  stable  closed,  and  with  ridge  ventilation,  it  is 
found  ^  that  the  current  of  air  rushes  in,  strikes  tlie  floor  at  a 
variable  distance  after  spreading  out  somewhat,  then  rises  and 
most  of  it  passes  out  at  the  ridge.  A  current  decreases  rapidly 
in  velocity  after  the  first  five  or  six  feet  from  the  inlet.  The 
atmosphere  immediately  under  the  inlet  is  l)ut  moderately  dis- 
turbed. 

When  opposite  windows  are  open,  the  air  comes  in  from  the 
windward  side,  strikes  the  ground,  rises  again,  and  a  consider- 
able portion  passes  directly  out  at  the  opposite  side.  But  a  sud- 
den change  in  the  outside  currents  may  temporarily  reverse 
this  series. 

The  exact  movement  of  air  within  the  stable  is  varied,  of 
course,  by  stall  partitions  and  other  obstructions. 

A  strong  wind  passing  over  a  stable  provided  with  ventilating 
shaft  has  an  outward  suction  effect,  and  this  is  increased  by  a 
properly  constructed  cap  which  does  not  permit  the  entrance 
of  outside  air  from  below. 

'  Paige. 


LECTURE  XXIII 

YENTILATION— Continued 

Stable  Construction 

Space  needed. — A  large  space — 500  cubic  feet  or  more  per 
animal — is  important;  but  this  does  not  lessen  the  necessity  for 
ventilation.  The  atmosphere  in  a  large  stable  housing  a  given 
number  of  animals  may  become  just  as  foul  as  that  in  a  smaller 
stable  with  the  same  number  of  animals,  the  only  difference 
being  the  length  of  time  required  to  reach  this  condition.  The 
larger  space  makes  possible  the  admission  of  a  sufficient  amount 
of  air,  without  such  drafts  as  would  be  the  result  if  the  same 
amount  of  air  per  hour  were  admitted  into  a  smaller  stable. 

Location. — In  order  that  a  stable  may  be  well  lighted  and 
well  ventilated,  it  is  necessary  to  exercise  care  in  selecting  the 
location  and  in  planning  the  proportions  of  the  building.  One 
of  the  most  desirable  forms  is  that  of  a  main  part  standing  east 
and  west  and  used  in  a  general  way  for  storage  purposes,  with 
one  or  two  "ells"  at  right  angles  to  this  on  the  south.  Such  an 
arrangement  gives  a  very  satisfactory  and  well-protected  yard 
on  the  south,  and  an  even  lighting  to  the  various  portions  of 
the  "ells"  in  which  the  animals  are  kept.  When  a  stable  ex- 
tends east  and  west,  and  is  wide  enough  for  two  rows  of  stalls, 
the  animals  on  the  north  side  do  not  get  much  sunlight,  and  the 
general  lighting  of  their  portion  of  the  stable  is  poor. 

Width. — To  be  capable  of  the  best  ventilation,  a  stable  should 
not  be  over  25  to  30  feet  in  width ;  and  the  lower  the  better 
within  reasonable  limits,  when  one  is  depending  on  ventilation 
by  doors  and  windows. 

Windows. — In  order  to  secure  suitable  ventilation  in  a  build- 
ing of  this  kind,  two  sets  of  windows  should  be  provided,  at  least 
one  set  on  each  side,  or  better  still,  two  sets  on  each  side,  one 
above  the  other.  Door  should  be  opposite  door,  and  window 
opposite  window  wherever  practicable.  Sweep  of  sunlight  over 
floor  and  fixtures  is  most  desirable. 

In  general  where  one  is  depending  upon  natural  ventilation, 

114 


VENTILATION 


115 


and  the  air  is  brought  in  cold,  the  inlet  should  be  high ;  the  out- 
let may  be  either  low  or  high,  and  controlled  by  a  damper  for 
cold  weather. 

Outlets  and  inlets. — In  cases  where  suitable  outlets  are  pro- 
vided above,  and  the  conditions  are  favorable,  warmed  air  passes 
upward  and  out  of  the  room  or  building ;  but  if  such  outlets  are 
not  provided,  then  heated  air  merely  rises  to  the  ceiling,  cools, 
spreads  out  and  descends,  and  no  pure  air  can  come  in  to  take 
its  place.     Circular,  straight  tubes  are  preferable.     It  is  esti- 
mated that  a  right-angle  bend  in 
an  outlet  diminishes  the  velocity 
of    the    outgoing    air    about    one 
half.    Where  it  is  absolutely  nec- 
essary that  an  outlet  tube  should 
change   its   course,   it   should  be 
done  in  a  curve  or  slight  bend 
rather  than  at  a  right-angle.    All 
parts    of    ventilator,  shafts     and 
tubes    should    l)e    accessible    for 
cleaning  purposes,  as  it  is  not  un- 
common for  them  to  become  so 
obstructed  by  cobwebs  and  dust 
as  to  be  useless.   In  a  general  way, 
the  outlet  tube,  if  it  must  be  near 
an  outside  wall,  should  be  placed 
on  the  south  side  of  the  building 
in  order  to  economize  the  heat  of  the  sun  in  rendering  it  more 
effective.     Central  outlet  tubes  are  generally  more  efficient,  be- 
cause they  cool  the  column  of  air  less,  and  maintain  the  current 
velocity  better.    One  or  two  outlet  tubes  are  more  efficient  than  a 
larger  number  and  should  be  preferred  whenever  construction 
permits. 

:\Iany  small  inlets  are  always  better  than  a  few  large  ones,  as 
they  admit  the  same  volume  of  air,  and  give  it  better  distribu- 
tion, without  direct  currents. 

Wing  describes  a  form  of  cupola  ventilation  which  has  been 
found  quite  satisfactory  in  providing  air  outlet  for  some  barns 
(see  Fig.  40).  This  cupola  outlet  seems  always  in  operation. 
There  is  no  chance  for  wind  to  blow  in  and  force  strong  down 
drafts.  When  in  working  order,  it  serves  always  as  an  outlet. 
It  is  easily  closed  by  a  rope  from  the  ground  floor. 


Fig.  39. — Ventilation.     (Paige.) 

1.  Air  duct  obstructed  by  cob- 
webs and  dust. 

2.  Stationary  outlet  cowl  to 
utilize  the  force  of  the  wind  for 
producing  upward  suction,  and  to 
prevent  down  draft. 


116 


VETERINARY  STUDIES 


Fig.  40. — Cupola  Ventilation. 


This   cupola   ventilator   consists   of    a   common    cupola   with 
doors  on  two  opposite  sides,  hinged  above. 

Connected  with  these  doors,  S,  0,  is  a  light  board  B,  cut  in 
the  middle  and  hinged.     When  this  board  is  straight,  it  holds 

one  or  both  doors  partly 
open.  If  the  wind  blows 
against  one  side,  that  door 
closes  and  the  lee  side  door 
opens.  To  close  both  doors 
pull  down  on  the  rope  E. 

Sheringham  windows. — 
The  Sheringham  window  is 
simple  and  efficient  for  a 
stable  of  suitable  construc- 
tion. The  system  consists  essentially  of  windows  hinged  at  the 
bottom  and  guarded  at  the  sides  so  as  to  make  troughs  as  the 
windows  open  inward.  This  gives  an  upward  current,  the  air 
passing  over  the  backs  of  the  animals  and  settling  down  without 
direct  current. 
There  should  pref- 
erably be  two  sets 
of  windows  on 
each  side,  the 
lower  windows  be- 
ing generally  used 
for  inlets  on  the 
windward  side, 
and  the  higher 
windows  for  the 
outlets  on  the  lee- 
ward side.  This 
affords  a  simple, 
inexpensive,  and 
easily  manipulated 
method  of  ventila- 
tion,  and  may  be 

combined  with  ventilating  shafts.  Outlet  ventilating  shafts 
should  have  openings  near  the  ceiling,  and  also  close  to  the  floor, 
so  that  their  use  can  be  regulated  according  to  season  and  tem- 
perature, the  upper  openings  of  the  shaft  being  used  in  hot 
weather,  and  the  lower  openings  in  cold  weather. 


Fig.  41. — Ventilation.     (Paige.) 

1.  Sheringham  window  in  section. 

2.  Sheringham   window,   opening   inward, 
from  outside. 


Seen 


VENTILATION  117 

There  should  be  a  number  of  medium-sized  or  even  small 
windows  in  this  system,  rather  than  a  few  large  ones.  The 
same  amount  of  air  can  be  allowed  to  enter  through  the  small 
openings  without  direct  draft  and  with  much  better  distribution. 

For  large  and  expensive  stables  there  are  systems  of  ventila- 
tion based  upon  Prof.  King's  work.  Competent  architects 
should  be  consulted  concerning  the  plans  or  the  Division  of 
Agricultural    Engineering    at    your    state    agricultural    college. 

Amount  of  ventilation  needed. — The  horse  passes  about  45 
cubic  feet  of  air  through  the  lungs  per  hour.  This,  then,  would 
be  the  amount  which  the  average  horse  would  use  if  he  were 
out  in  the  open  where  the  supply  is  inexhaustible.  It  is  impos- 
sible to  have  the  air  of  any  occupied  stable  as  pure  as  the  out- 
side atmosphere.  The  purpose  of  ventilation  is  to  come  as  near 
to  this  point  as  may  be  feasible. 

Air  passing  at  the  rate  of  3  miles  per  hour,  which  is  barely 
perceptible,  through  total  openings  equal  to  1  foot  square,  ad- 
mits 15,840  cubic  feet  per  hour.  Inlet  openings  amounting  to 
4  square  feet  admitting  a  current  of  air  moving  at  the  average 
rate  of  3  miles  per  hour  under  average  weather  conditions  are 
estimated  to  provide  sufficient  ventilation  for  20  cows. 

The  following  data  will  serve  as  a  general  guide : 

RELATIVE   AMOUNT   OP   AIR   BREATHED 

Horse  100 

Cow   82 

Hos-  32 

Sheep  21 

AIR    NEEDED   PER   HOUR    (King) 

Horse -^290  cubic  feet 

Cow    3o42       "        " 

Ho-  v.m     "      " 

Sheep  917       "        " 

Hen    35      "        " 

Professor  Stewart,  University  of  Minnesota,  has  worked  out 
the  following  useful  data  for  low  outside  temperatures : 

The  amount  of  air  that  should  be  pi-ovided  per  cow  ])or  hour 
is  estimated  by  Stewart  as  follows:  At  —  10°  F,  1800  cul)ic  feet; 
at  0°  F,  2400 ;  at  +  10°  F,  3000.  This  assumes  an  indoor  tem- 
perature of  35°  to  37°  F,  and  a  stable  of  average  construction. 


118  VETERINARY  STUDIES 


TOTAL   OUTLET   AREA    NEEDED    AT   VARYING   HEIGHTS    (Stewart) 

Outlet  40  feet  hiiili  horse  24,  cow  20    square  inches, 

"       30     "       "  "      30,      "     25         ''            " 

"       20     "       "  "      36,      "     30,  hog  20,    sheep  12  square  inches. 

"      15     "       "  "     42,      "     36,     "    25,       "      15       "          " 

These  figures  also  assume  that  the  outlet  tube  is  vertical  and 
straight. 

If  the  outlet  shaft  is  not  vertical  or  straight,  then  the  capacity 
should  be  increased  accordingly. 


LECTURE  XXIV 
FOOD  AND  WATER 

Food. — Food  may  be  a  factor  in  animal  disease  when  it  is 
excessive  in  amount,  insnt^cient,  too  concentrated,  too  coarse, 
bulk}',  and  innutritions  for  the  animal  that  receives  it;  when  it 
is  poor  in  quality,  when  given  in  a  poorly  balanced  ration  or  at 
irregular  or  improper  intervals,  or  to  a  very  tired  or  hot  ani- 
mal ;  when  carrying  vegetable  or  animal  parasites,  or  when  sud- 
denly changed,  as  from  poor  to  rich  pasture ;  and  when  poi- 
sonous. 

Excessive  amount  results  in  azoturia,  heaves,  colic,  etc.,  among 
horses ;  and  in  milk  fever,  etc.,  among  cows.  It  favors  the  de- 
velopment of  all  febrile  diseases.  Only  a  certain  amount  of 
food  can  be   absorbed   or  used ;   the   remainder   causes   trouble. 

Deficiency  predisposes  to  all  diseases  that  are  favored  by  a 
lessened  vitality.  The  deficiency  may  be  total,  or  there  may  be 
one  or  more  special  deficiencies,  for  example,  deticiency  of  vita- 
min}?, which  are  essential  to  normal  growth,  and  health ;  or  de- 
ficiency of  certain  mineral  matters,  the  lack  of  which  impairs 
growth  and  development  of  framework.  Such  animals,  particu- 
larly hogs,  tend  to  "go  down."  Lack  of  iodin  for  the  pregnant 
sow  i)roduces  pigs  that  are  born  without  hair,  weak  and  with 
goiter.  Glanders  and  similar  diseases  are  especially  apt  to  oc- 
cur, or  to  increase  in  severity,  among  horses  that  are  poorly  fed. 
Deficiency  in  mineral  matters  predisposes  toward  certain  dis- 
eases of  bone.  Deficiency  of  albumin  results  in  loss  of  energy 
and  strength,  and  animals  so  fed  are  apt  to  be  languid  and 
weak. 

Coarse,  hulkij,  and  innutritimis  food  may  cause  colic,  indiges- 
tion, heaves  and  impactions,  particularly  in  animals  with  small 
stomachs,  as  the  horse. 

Poor  quality,  hay  cut  too  ripe  or  that  has  been  rained  on  after 
cut,  light  oats,  etc.,  causes  tlie  same  disorders  as  deficienc}',  and 
also  favors  colic,  impactions,  and  anemia. 

119 


120  VETERINARY  STUDIES 

A  food  may  be  poorly  balanced  and  dangerous  though  very 
nutritious.  Beans,  wheat,  oil  meal,  and  cotton  seed  meal  fed 
alone  contain  too  much  protein  and  not  enough  ash,  fat  and 
carbohydrates  and  crude  fiber.  When  fed  in  the  unbalanced 
ration,  such  excess  of  protein  may  cause  febrile  disturbances, 
diarrhea,  congestion  of  the  liver,  azoturia  and  milk  fever.  A 
similar  excess  of  carbohydrates  or  fats  may  cause  an  injurious 
deposition  of  fat  under  the  skin  into  and  between  the  fibers  of 
voluntary  muscles,  or  in  the  heart  or  liver.  Excess  of  fats 
causes  diarrhea  and  checks  absorption. 

Faulty  intervals  interfere  with  digestion  and  thrift,  and  may 
cause  such  disorders  as  colic  and  impaction.  Cows  may  be  fed 
at  longer  intervals  than  horses;  but  both  should  be  fed  regu- 
larly. A  horse  that  goes  a  long  time  without  food  and  then  gets 
an  abundance  is  apt  to  have  colic  or  founder.  The  calf  that 
goes  past  its  usual  feeding  time  and  then  overeats,  is  very  apt 
to  have  serious  bowel  trouble  and  remain  unthrifty  for  a  long 
time. 

Animal  parasites  infest  several  foods,  e.g.  stomach  worms  (of 
sheep)  on  grass. 

Sudden  changes,  from  poor  to  rich  pastures,  favor  hoven,  im- 
paction, and  blackleg. 

There  are  class'  differences — some  animals  may  eat  with  im- 
punity what  others  cannot.  By  first  producing  digestive  dis- 
turbances, rich  cereals  may  indirectly  cause  laminitis  in  horses, 
— not  in  cows  however.  Pigs  can  eat  acorns  freely ;  but  acorns 
are  injurious  to  other  animals. 

Paisonoiis  food,  such  as  poisonous  plants,  may  cause  heavy 
losses.  Such  plants  are  usually  distasteful  to  stock  and  are  not 
eaten  unless  animals  are  hungry,  for  example,  when  on  scant 
pasture  or  after  long  shipment  by  rail.  Such  losses  are  nearly 
all  preventable  by  wise  management. 

"Wild  cherry"  and  black  cherry  leaves  and  occasionally 
sorghum  contain  a  deadly  poison,  prussic  acid.  As  a  rule  cherry 
leaves  are  not  eaten,  but  losses  of  cattle  and  sheep  from  such 
poisonous  plants  have  been  reported  many  times. 

The  common  sorghum  plant  sometimes  contains  the  same 
poison  as  cherry  leaves.  Fortunately  it  is  unusual  for  sorghum 
to  be  poisonous,  but  serious  losses  of  cattle  have  occurred  be- 
cause of  it.  It  is  safer  to  test  a  field  of  fodder  sorghum  by 
turning  in  only  one  or  two  animals  the  first  day. 


FOOD  AND  WATER  121 

Laurel  leaves  are  poisonous  and  cause  losses  among  sheep 
particularly. 

^Yild  larkspurs  have  caused  heavy  losses  of  cattle  and  sheep, 
especially  on  western  ranges. 

WJiorlcd  ))iilkwccd  is  very  poisonous  especially  to  sheep. 

^Vatcr  hemlock  (-wild  parsnip),  is  poisonous  to  all  classes  of 
stock,  and  of  all  plants  likely  to  be  eaten,  is  considered  the  most 
dangerous. 

Loco  plants  are  poisonous.  Their  damage  is  of  slow  develop- 
ment. Horses,  cattle  and  sheep  on  the  western  ranges  are  often 
poisoned  by  it.  This  plant  is  peculiar  among  stock  poisons  in 
that  it  creates  a  drug  habit  in  stock  similar  to  the  opium  habit 
of  people. 

Roots,  like  sugar  beets  and  mangels,  are  not  poisonous,  but 
when  fed  in  excess — to  sheep  at  least — are  likely  to  cause  seri- 
ous derangement  of  the  urinary  organs,  with  formation  of  cal- 
culi (stones)  in  the  kidneys,  ureters,  or  bladder.^ 

Water 

Water. — Water  may  be  a  factor  in  animal  disease  when  it  is 
excessive  or  deficient  in  amount;  when  it  contains  bacteria,  e.g. 
the  virus  of  glanders  or  of  hog  cholera  ;  or  when  it  contains  such 
low  forms  of  animal  life  as  intestinal  parasites  for  example; 
when  it  has  received  sewage  matter ;  when  it  is  very  hard,  when 
it  is  given  at  improper  intervals  or  in  large  quantity  soon  after 
eating,  or  when  it  is  given  in  large  quantities  to  a  very  hot  or 
tired  horse. 

An  excessive  amount  of  water  is  said  to  lessen  the  digestibility 
of  foods,  increase  tissue  waste,  and  favor  indigestion. 

A  deficient  water  supply  may  cause  impactions  in  cattle  and 
lessen  the  excretions  from  skin  and  kidneys  in  horses.  Horses 
need  about  2  pounds  and  cows  giving  milk  about  3.5  to  4  pounds 
of  water  per  pound  of  dry  food,  the  amount  varying  according 
to  diet  and  condition  of  the  atmosphere.  Cows  need  much  more 
tlian  horses  in  proportion  to  weight  and  feed,  and  can  usually 
be  trusted  to  drink  at  tlieir  own  pleasure.  Horses  will  fre- 
quently drink  too  much,  especially  when  tired  or  liot. 

^  Iowa  Exp.  Sta.  Bui.  112.  For  detailed  information  concerning  poison- 
ous plants,  consult  "Poisonous  Plants"  by  Paniniel;  also  Bulletin  20, 
and  Bulletin  57;1 — both  relating  to  poisonous  plants  and  published  hj 
U.  S,  Dcpt.  Agr.  Bureau  of  Animal  Industry. 


122  VETERINARY  STUDIES 

Bacteria  frequently  contaminate  drinking  water,  which  may 
thius  serve  as  a  source  of  transmission  for  many  germ  diseases; 
like  anthrax,  foot  and  mouth  disease,  hog  cholera,  and  glanders. 

Animal  paradtcs  also  contaminate  the  water  supply,  which 
serves    to    spread    parasitic    diseases,    intestinal    parasites,    for 

example. 

Hard  water  may  contain  much  calcium,  magnesium,  etc.,  and 
is  said  to  cause  indigestion,  unthrifty  conditions,  and  perhaps 

calculi. 

Intervals  may  be  w^rong.  Horses  should  be  watered  regu- 
larly and  at  as  short  intervals  as  convenient.  They  should  not 
be  given  large  quantities  of  water  sooner  than  one  hour  after 
eating  gi-ain.  Much  cold  water  interferes  with  digestion,  and 
w^hen  given  to  a  very  hot  or  tired  horse  may  result  in  founder 
or  indigestion. 

Practical  application. — With  this  lesson  in  mind,  the  student 
should  hereafter  watch  for  milk  fever  cases  to  see  if  the  cow  has 
not  been  in  good  condition  and  rather  heavily  fed  for  a  cow  not 
milking,  and  lacking  in  exercise. 

He  should  be  on  the  watch  for  azoturia  (see  Lect.  XLIV)  and 
learn  whether  the  horse  has  not  been  idle  and  full  fed  during 
the  day  or  so  prior  to  illness.  Note  also  whether  there  had  not 
been  a  period  of  regular  work  on  full  feed  before  this  idle 
period. 

He  should  also  watch  for  cases  of  heaves  among  horses  to 
determine  whether  such  horses  have  been  greedy  eaters  and 
heavily  fed  with  dusty  hay  or  other  bulky  food.  It  will  be 
interesting  for  the  student  to  be  on  the  lookout  for  an  outbreak 
of  hog  cholera  in  a  herd  that  had  access  to  a  small  pond  or  very 
sluggish  stream,  to  see  if  there  is  not  an  unusually  heavy  loss 
in  such  a  case. 

The  very  hot,  very  tired,  or  very  hungry  horse  should  be 
fed  and  watered  cautiously,  with  small  quantities,  until  he  is 
in  better  condition.  Sudden  and  radical  changes  from  old  to 
new  feed  of  the  same  kind  are  to  be  avoided.  The  quantity  and 
quality  should  be  watched.  Too  much  hay  is  the  most  common 
error  made  in  the  feeding  of  horses.  The  working  horse  in  good 
condition  should  be  fed  but  little  on  holidays.  For  the  heavily 
pregnant  mare,  excessive  feeding  is  injurious  and  especial  care 
must  be  taken  to  prevent  colic  in  such  a  mare. 

Diseases    often    associated   with    overfeeding    are:    azoturia, 


FOOD  AND  WATER  123 

IjTiiphangitis,  heaves,  founder,  garget,  calf  cholera,  colic,  etc. 
Feeding  and  watering  should  be  so  managed  as  to  avoid  dis- 
semination of  disease,  for  example  tuberculosis  in  cattle.  Given 
a  common  feeding  and  watering  trough,  so  that  food  or  drink 
can  be  infected  by  a  diseased  animal,  and  then  taken  by  another, 
the  spread  of  disease  may  be  rapid. 

Such  a  case  is  well  illustrated  by  a  common  cement  feed  and 
water  trough,  where  water  comes  in  at  one  end  of  the  trough 
and  flows  past  the  cattle  to  the  lower  end.  One  diseased  animal 
at  the  upper  end  may  contaminate  the  feed  and  water  for  many. 


PARASITIC  DISEASES 

LECTUEE  XXV 
PARASITISM 

Parasitism  may  be  temporary  or  permanent,  external  or  in- 
ternal. 

Parasites  of  domestic  animals  cause  greater  losses  than  is  gen- 
erally realized.  Every  stockman  should  be  informed  concerning 
the  most  common  and  serious  parasites,  especially  those  of  sheep. 
Parasitism  may  be  temporary  when  only  a  portion  of  the  para- 
site's life  history  is  with  one  host;  permanent,  when  its  whole 
life  history  is  with  the  same  host;  external  or  internal,  when  it 
affects  the  body  surface  or  the  internal  organs. 

Sources  and  causes  of  parasitic  diseases. — Parasites  may  be 
received  into  the  digestive  apparatus  with  food  or  drink,  they 
may  gain  entrance  through  the  respiratory  tract,  or  broken 
skin;  or  there  may  be  external  infection  by  contact,  as  with  lice 
or  scab  and  mange  mites. 

Nourishment. — Some  parasites  have  mouth  and  digestive  or- 
gans, e.g.,  roundworms  of  the  intestines;  others  receive  their 
nourishment  by  surface  absorption  or  osmosis,  e.g.,  tapeworms. 

Effect  on  health  of  host. — This  depends  on  the  organ  or  or- 
gans invaded,  the  rapidity  of  multiplication,  the  amount  of 
nutrition  used  by  parasite,  and  the  amount  of  irritation  caused. 

Intestinal  parasites  cause  trouble  by  obstruction,  by  irritating 
and  abstracting  blood  from  the  mucous  membrane,  by  mechani- 
cal irritation,  and  by  using  nutrition.  Hence,  we  have  symp- 
toms of  indigestion,  colic,  and  unthrift. 

Liver  parasites  cause  jaundice  and  general  anemia. 

Lung  and  bronchial  parasites  cause  bronchitis  or  pneumonia. 

Parasites  in  the  hlood  vessels  cause  disease  of  the  vessel  walls, 
and  may  indirectly  cause  obstructions  and  colic. 

Parasites  in  the  hraim  are  more  rare,  and  usually  fatal. 

Parasites  in  muscidar  tissue  may  cause  little  disturbance  to 

the  animal  host,  but  be  very  serious  to  human  health ;  e.g.,  pig 

measles  and  trichina. 

124 


PARASITISM  125 

General  treatment. — Medical  treatment  must  be  siu-h  as  will 
destroy  or  remove  the  parasites.  Medicines  may  aid  in  remov- 
ing parasites  by  suffocating  them,  by  poisoning  them,  or  by  caus- 
tic or  irritating  chemical  effect  on  the  parasites.  Many  para- 
sites disappear  at  a  certain  stage  by  means  of  their  own  activity 
and  habits;  e.g.,  ticks,  bots  in  horses,  grubs  in  backs  of  cattle, 
•and  grubs  in  the  nasal  passages  and  head  cavities  of  sheep.  It 
is  well  to  remember  also  that  many  parasites,  bots  in  the  horse's 
stomach  for  instance,  can  resist  stronger  medicines  than  the 
organs  or  tissues  they  invade. 

Practical  suggestions. — Parasitism  would  l)e  impossible  if 
everything  that  comes  in  contact  with  the  animal  body  were  free 
from  parasites.  Saddles,  harness,  blankets,  posts,  and  fences 
are  the  usual  agents  which  spread  Texas  itch  or  mange  among 
horses;  intestinal  worms  generally  gain  entrance  in  the  egg  or 
immature  form,  with  the  food  or  drinking  water. 

Parasitic  diseases  may  often  be  prevented  by  forethought 
and  wise  management.  Intestinal  parasites  of  sheep,  like 
stomach  worms,  module  disease,  tapeworms,  etc.,  may  be  largely 
prevented  by  change  of  grazing  ground — pasture,  meadow, 
stubble,  millet,  sorghum,  rape,  etc. 

Serious  trouble  from  lice  in  winter  should  be  prevented  by 
proper  treatment  in  the  fall,  while  the  weather  is  still  warm 
enough  for  vigorous  treatment  by  dipping  or  w^ashing. 

In  many  cases,  the  parasite  requires  two  hosts,  living  its  im- 
mature stage  in  one  host,  and  its  mature  stage  in  another.  Cer- 
tain immature  tape  worms  which  cause  losses  in  sheep,  use  the 
dog  for  their  mature  form  host.  Unnecessary  association  of  dogs 
and  sheep  on  feeding  ground  is  therefore  unwise. 

Ponds,  wells  which  receive  surface  drainage,  sluggish  streams 
and  marshes,  shoukl  thei-efore  be  regarded  with  suspicion. 
Sound  animals  should  not  be  allowed  in  sheds,  yards,  or  barns 
where  animals  diseased  by  external  parasites,  like  lice  or  scab 
mites,  have  been,  until  such  structures  have  been  disinfected. 
Intestinal  worms  w^hich  appear  in  the  manure  of  horses  should 
be  destroyed  with  boiling  water, — not  merely  crushed  and 
thrown  aw^ay. 

External  Parasites 

Lice. — These  are  wingless  insects  classified  into  two  general 
groups,   biting  lice  and  sucking  lice.     Each   of   these   general 


126  VETERINARY  STUDIES 

groups  is  subdivided  into  various  families  and  species.  As  a 
rule  they  are  specific,  i.e.,  a  certain  species  of  louse  is  parasitic 
only  on  a  certain  species  of  bird  or  animal.  In  size,  they  vary 
greatly  from  mere  specks  to  the  giant  hog  louse  which  may 
be  1/5  of  an  inch  long. 

Lice  infect  especially  certain  portions  of  the  body  surface  of 
each  animal,  e.g.,  for  cattle,  the  back ;  for  hogs,  back  of  the  ears, 
for  poultry,  the  fluff  and  under  the  wings;  for  young  chickens, 
the  top  of  the  head. 

Reproduction. — Lice  reproduce  by  eggs  (nits)  glued  to  hairs 
or  feathers.    The  eggs  are  very  light  in  color  and  oval  in  shape. 

Treatment. —  (1)  Bathe  the  affected  parts 
with  corrosive  sublimate  in  vinegar,  15 
grains  to  the  pint;  or  (2)  tobacco  water, 
prepared  by  steeping  for  an  hour  2  ounces 
of  tobacco  to  each  quart  of  water;  or  (3) 
Professor  Riley's  kerosene  emulsion  made 
by  mixing  kerosene  2  gallons,  soft  soap  one 
half  pound,  water  1  gallon.  Dissolve  the 
soap  in  water  and  add  kerosene  slowly  while 
the  water  is  still  boiling.    Churn  10  minutes 

Fig.    42.— Cattle     ^^^^^  ^^^'  ^^^®'   dilute  by  adding  8  times  its 
Louse.    Female.        bulk  of  water.     This  is  cheap,  harmless,  and^ 
H  aematopinus      satisfactoiy. 

eurysternus.  Yqy    cattle,    control    lice    by    dipping    or 

other  thorough  treatment  in  the  fall  before 
cold  weather.  Use  any  good  coal  tar  dip  2  to  3  per  cent  and 
repeat  in  about  10  days.  Any  treatment  for  lice  should  usually 
be  repeated  several  times  at  intervals  of  10  to  20  days,  depend- 
ing on  season,  the  shorter  interval  for  warmer  weather.  It  is 
usually  advisable  to  whitewash  stalls  and  sheds.  All  harboring 
litter  should  be  removed  and  burned.  Brushes,  combs,  etc., 
must  also  be  treated.  Clipping  is  a  great  aid  in  the  treatment 
of  external  parasitism.  In  fact,  it  is  difficult  to  treat  sheep 
successfully  for  either  lice,  sheep  tick,  or  scab  without  shear- 
ing. 

Water  solutions  and  oils  are  usually  inadvisable  in  cold 
weather.  For  treating  cattle,  horses,  and  young  stock  in  cold 
weather,  dust  frequently  into  the  hair  along  neck,  back,  and 
rump,  either  Persian  insect  powder  or  powdered  sabadilla  seed 
and  sulphur  equal  parts,     A  little  kerosene  oil  on  a  brush  and 


PARASITISM  127 

used  frequently,  is  safe  and  helpful  if  done  with  reasonable  cau- 
tion. Volatile  substances,  especially  wood  alcohol,  are  effective, 
dry  rapidly,  are  moderate  in  cost,  and  are  safe  in  cold  weather, 
when  reasonably  used.  They  are  more  effective,  also,  than  a 
powder.  Powdered  sodium  tluorid  is  effective  for  biting  lice  but 
not  for  sucking  lice. 

For  poultry  use  whitewash  in  abundance,  and  plenty  of  fine, 
air-slaked  lime  dusted  into  the  nests  and  on  the  floor.  It  is  a 
good  plan  to  throw  this  lime  against  the  wall,  so  that  it  will 
float  in  the  air  and  then  gradually  settle  down  into  crevices  and 
over  the  poultry.  Or  kerosene  may  be  sprayed  over  the  walls 
and  ceiling  and  the  perches  frequently  washed  with  it.  Kero- 
sene is  cheap,  can  be  rapidly  applied,  and  is  very  effective. 
Constant  access  to  dust  bath  of  dust  or  sifted  ashes,  air-slaked 
lime,  sulphur,  and  Persian  insect  powder,  should  be  given  and 
the  poultry  house  should  be  kept  dry. 

Flies. — At  times  flies  prove  a  serious  nuisance  for  domestic 
animals,  particularly  horses  and  cattle.  Various  preparations 
have  been  tried  at  different  experiment  stations  with  fairly  sat- 
isfactory results. 

No.  1. — Was  tested  and  reported  as  satisfactory  by  the 
Nebraska  Experiment  Station:  Oil  of  wood  tar  1  part;  neutral 
oil  (a  petroleum  product)  4  parts.  Mix  and  shake  thoroughly. 
A  very  light  application  of  this  should  be  made  by  brush  or 
spray.  It  is  occasionally  necessary  to  sponge  off  the  hair  with 
a  cloth,  using  a  little  of  the  neutral  oil  on  account  of  a  little  gum 
which  collects  with  repeated  application. 

The  following  (Jensen)  is  probably  still  better:  Dissolve  1 
pound  naphthaline  in  about  V/o  gallons  crude  oil,  applying  just 
sufficient  heat  to  effect  solution.  Add  to  this  1  gallon  of  fish  oil. 
In  a  separate  vessel,  dissolve  about  21/2  pounds  of  common  laun- 
dry soap  in  about  5  gallons  of  water.  When  the  soap  solution 
is  complete,  mix  it  with  the  oils  and  naphthaline,  put  it 
into  an  old  churn  and  work  it  thoroughly  together,  adding 
gradually  sufficient  water  to  make  the  product  measure  10  gal- 
lons.    Apply  daily  or  twice  a  week  as  needed  with  brush  or 

spray. 

Sheep  tick  (Melophagus  ovinus). — This  is  not  a  true  tick  but 
a  wingless  fly.  The  young  larvae  are  attached  at  birth  to  the 
wool  fibers.  The  pupa  stage  last  from  three  to  six  weeks,  after 
which  maturity  is  reached.    It  is  a  permanent  parasite,  i.e.  the 


128 


VETERINARY  STUDIES 


Fig. 


43. — Sheep   Tick   and   Enlarged 
Proboscis. 


entire  life  history  is  passed  on  the  sheep  host.  The  mature 
tick  pierces  the  skiu  in  order  to  suck  blood,  thus  causing  serious 
irritation  and  unthrift. 

The  treatment  commonly  used  is  coal  tar  dip,  2  or  3  per  cent 
applied  after  shearing.  The  wool  must  be  stored  where  the 
dipped  sheep  cannot  become  reinfected  from  it. 

Dipping  should  be  repeated  in  from  twenty  to  forty  days 
depending  on  the  weather.     Lambs  must  be  protected  during 

shearing  time,  otherwise 
the  ticks  will  leave  the  older 
sheep  and  go  to  the  lambs. 
Sheds,  pens,  etc.,  must  be 
cleaned  and  disinfected  a.s 
for  lice. 

Ticks. — True  ticks  are 
temporary  parasites,  com- 
monly found  in  brush  and 
tall  grass. 

Life  History. — The  j'oung 
female  crawls  up  on  brush 
or  grass  or  weeds  and 
waits  for  some  animal  to 
come  along  and  brush  her 
off.  She  soon  attaches  to  the  skin,  gorges  with  blood,  and 
drops  off.  After  a  few  days,  she  begins  laj'ing  several  thousand 
eggs  and  dies  soon  afterward.  The  eggs  hatch  in  15  to  20  days 
if  conditions  are  favorable. 

Treatment. — Any  safe  oily  preparation  may  be  used  to  de- 
stroy the  common  ticks.     (See  Texas  Fever  for  dipping.) 

Ringworm. — This  disease  appears  most  commonly  on  the  heads 
and  necks  of  cattle,  especially  calves;  but  man  and  all  domestic 
animals  are  also  subject  to  it.  It  is  caused  by  a  vegetable  para- 
site (Trichopliyton)  growing  in  the  skin,  somewhat  like  mil- 
dew in  a  grape  leaf.  This  disease  appears  in  the  form  of  round, 
raised,  and  bald  patches,  especially  on  the  heads  and  necks  of 
calves  during  the  winter.  The  patches  are  scaly  or  crusty,  an 
inch  or  two  across;  the  hairs  stand  erect,  then  split  and  break. 
There  are  usually  several  such  patches  close  together.  Ring- 
worm spreads  readily  by  inoculation.  It  is  not  especially  seri- 
ous; but  it  is  disagreeable. 

A   good  method  of  treating  ringworm   is  to  use   scrubbing 


Melophagus  ovinus.    Properly  a  sheep 
louse. 


PARASITISM  129 

brush,  soap,  and  warm  water;  then  apply  every  other  day  10  per 
cent  carbolic  acid  in  glycerin  or  tincture  of  iodin  and  glacial 
acetic  acid  in  equal  parts.  Care  must  be  taken  not  to  get  this 
into  the  eyes. 


LECTUEE  XXVI 
SHEEP  SCAB 

Sheep  scab  is  a  result  of  irritation  of  the  skin,  caused  by 
mites,  minute  animal  parasites  that  puncture  the  skin  from 
the  surface  or  burrow  tunnels  in  it. 

There  are  three  common  types  of  these  mites  and  three  types 
of  the  disease  which  they  cause.  One  variety  of  mites  produces 
body  scab,  another  head  scab,  and  a  third  foot  scab.  Body  scab 
is  the  most  common,  the  others  are  relatively  unimportant. 

Mites  are  permanent  parasites,  their  entire  life  history  being 
spent  on  one  host ;  they  multiply  with  enormous  rapidity. 

Body  Scab 

Body  scab  is  caused  by  mites  (Psoroptes)  which  have  power  of 
free  movement  upon  the  surface.  It  is  the  most  common  and 
serious  type  of  scab.  This  type  spreads  most  rapidly  over  the 
individual  body,  and  also  rapidly  through  the  flock  and  from 
flock  to  flock. 

General  history. — This  disease  is  likely  to  become  serious 
before  being  noticed  by  the  owner.  The  parasites  which  cause 
this  type  of  the  disease  do  not  tunnel  into  the  skin,  but  cause 
intense  irritation,  especially  when  the  sheep  are  warm.  The 
owner  will  usuallj^  remember,  after  he  has  become  aware  that 
body  scab  exists  in  his  flock,  that  his  sheep  have  seemed  uneasy 
and  that  they  have  been  rubbing  and  biting  themselves  occa- 
sionally for  some  time. 

After  the  disease  is  under  way,  the  parasites  live  beneath  the 
crusts,  and  constantly  migrate  outward,  while  the  skin  slowly 
heals  in  the  center.  The  fleece  of  scabby  sheep  is  usually  rough, 
and  the  wool  matted  in  places  and  easily  rubbed  ofi'.  The  para- 
sites which  cause  this  form  of  the  disease  confine  their  work 
almost  exclusively  to  parts  of  the  body  where  the  wool  is  long 
and  thick. 

130 


SHEEP  SCAB 


131 


How  spread. — This  form  of  the  disease  spreads  rapidly 
through  the  Hock ;  because  of  the  location  of  parasites  upon  the 
body  of  the  sheep,  and  because  of  the  freely  moving  habits  of 
the  parasites.  As  a  rule,  the  disease  spreads  most  rapidly  in 
autumn  and  winter,  because  the  wool  is  then  long  and  thick, 
furnishing  favorable  conditions  for  the  parasites,  and  because 
the  sheep  are  kept  in  closer  contact  at  these  seasons.  The  dis- 
ease makes  more  rapid  progress  then  and  is  much  more  fatal 


Fig.  44. — A  Plain  Case  of  Sheep  Scab. 


with  the  weaker  sheep.  These  parasites  may  be  transferred  from 
one  sheep  to  another  in  a  great  variety  of  ways ;  for  instance, 
tags  of  wool  may  be  rubbed  off  and  dropped  almost  anywhere. 
Diseased  sheep  infect  posts  and  fences  by  rubbing  against  them, 
also  the  parasites  escape  from  one  sheep  to  another  Avhile  the 
sheep  are  in  close  contact  in  yards  and  sheds.  A  loaned  buck 
is  liable  to  bring  back  scab. 

Open  pastures  and  yards  usually  become  safe  again  after 
two  months.  Indoor  pens,  sheds,  etc.,  once  infected,  may  not 
be  safe  in  less  than  a  year  without  radical  cleaning  and  dis- 
infection. 

Foot  Scab 

The  disease  caused  by  foot  scab  mites  (Chorioptes)  appears 
on  the  feet  and  limbs.     The  diseased  area  extends  very  slowly, 


132 


VETERINARY  STUDIES 


but  may  eventually  reach  the  body.  This  form  of  scab  also 
spreads  very  slowly  from  one  animal  to  another.  Sheep  which 
are  infected  with  it  are  apt  to  be  almost  constantly  stamping 
and  pawing. 

Local  treatment, — Any  of  the  sheep  dips  recommended  for 
body  scab  may  be  used  to  treat  this  form  of  the  disease.  A  10 
per  cent  solution  of  the  creolin  is  simple,  safe,  and  easily 
applied  on  small  areas. 


Male. 


Fig.  45. — Sheep  Scab  Mites. 


Psoroptes,     male     (Cur- 
tice).   Body  scab. 


Sarcoptes   (Lugger). 
Head  seab. 


J'°fms)e. 

Sarcoptes   (Pevtit). 
Head  scab. 


Any  dip  or  ointment  that  will  kill  the  parasites  is  sufficient 
early  in  the  disease,  but  it  may  be  necessary  in  old  cases  to 
soften  the  scabs  by  a  little  oil  or  a  thorough  scrubbing  with 
brush  and  hot  soapsuds. 

Head  Scab 

The  mites  (Sarcoptes)  which  cause  head  scab  burrow  tunnels 
in  the  skin.  The  eggs  are  deposited  in  these  tunnels  and  there 
hatched.  This  type  of  scab  may  appear  on  almost  any  portion 
of  the  head.  It  may  slowly  invade  the  neck  and  other  portions 
of  the  body  where  the  wool  is  short ;  but  it  is  less  common  and 
less  serious  than  body  scab. 


General  Prevention 

Prevention  is  more  important  than  treatment  in  any  case 
where  it  can  be  secured,  because  it  is  surer,  it  is  cheaper,  and 
is  usually  much  easier  to  administer  than  treatment. 

Spread  of  scab. — Whether  the  scab  spreads  rapidly  over  the 
body  or  not  depends  to  some  extent  upon   the  thriftiness  or 


SHEEP  SCAB  133 

unthriftiness  of  the  individual  animal.  When  sheep  are  fat  and 
the  wool  is  well  supplied  with  yolk,  this  disease  spreads  more 
slowly,  and  is  much  less  serious.  The  infection  is  frequently 
made  when  one  sheep  rubs  against  posts  or  fences  where  scabby 
sheep  have  previously  rubbed.  In  the  latter  case,  the  mites  are 
first  transferred  from  the  diseased  sheep  to  the  post,  and  then 
from  the  post  to  the  healthy  sheep.  In  other  cases,  the  mites 
are  transferred  when  a  diseased  sheep  rubs  against  a  healthy 
one. 

Precautions. — Pens,  sheds,  and  yards  which  have  held  scabby 
slieej)  should  be  thoroughly  cleaned  and  disinfected;  and,  unless 
tiie  disinfection  is  very  thorough,  they  should  not  be  used  for 
sheep  until  at  least  four  weeks  have  elapsed.  It  is  supposed 
that  a  hard  rain  will  practically  disinfect  ground  surfaces,  but 
not  fences  and  posts.  Fields  and  pastures  in  which  scabby  sheep 
have  been  held  should  not  be  used  again  until  after  an  interval 
of  several  weeks,  and  preferably  not  until  after  a  heavy  rain. 

General  Symptoms 

History  and  diagnosis. — At  the  point  of  infection  there  oc- 
curs the  puncture ;  then  a  little  pimple,  soft  on  top,  which  rup- 
tures, a  little  fluid  escaping.  Dust  and  other  foreign  matter 
collect  in  this  fluid,  the  initial  scab  is  started,  and  the  diseased 
area  spreads. 

Affected  sheep  are  usually  uneasy  and  are  seen  scratching 
against  posts,  rubbing  against  other  sheep,  and  even  biting  the 
itching  surface.  The  irritation  is  most  noticeable  when  the 
sheep  are  heated,  as  by  exercise,  or  confined  in  a  close  room. 
At  first  the  wool  hangs  in  tags,  the  sheep  begin  to  pull  out  por- 
tions of  the  wool  with  the  mouth,  and  the  skin  becomes  bare  in 
patches  which  increase  as  the  mites  spread,  irritating  and  in- 
flaming the  skin.  To  determine  the  presence  of  the  mites,  scrape 
off  some  of  the  scab  and  a  little  of  the  healthy  skin  near  the 
border  of  the  scab.  Place  these  scrapings  upon  some  smooth 
black  surface  in  warm  sunshine,  and  examine  with  a  good  hand 
lens.  The  mites  may  then  be  seen  as  minute  white  bodies  about 
1/50  of  an  inch  long.  They  are  most  certainly  recognized  when 
they  are  seen  to  move.  It  is  sometimes  difficult  to  distinguish 
otherwise  betw'een  the  mites  and  particles  of  liglit-colored  dust 
or  epithelial  scales  from  the  skin  surface.     One  is  more  apt  to 


134  VETERINARY  STUDIES 

find  the  mites  where  the  skin  is  greasy  and  glistening,  and  not 
where  the  skin  is  dry  and  dull.  It  should  be  borne  in  mind 
when  examining  a  case  of  head  scab  that  the  mites  which  cause 
this  disease  burrow  beneath  the  surface  of  the  skin,  so  that  it 
is  necessary  to  scrape  deeper  than  for  ordinary  body  scab. 

Possible  mistakes. — It  is  well  to  bear  in  mind,  also,  that  other 
conditions  may  be  mistaken  for  sheep  scab,  particularly  dis- 
orders of  the  skin  produced  by  other  external  parasites,  such 
as  lice  and  sheep  ticks.  These  are  easily  seen  and  they  do  not 
cause  any  marked  local  lesion.  Skin  thickening  is  quite  char- 
acteristic of  scab,  but  not  in  the  case  of  ticks  or  lice.  In  the 
so-called  "wild  fire"  of  sheep  in  northwestern  states,  the  skin 
is  red,  but  not  thickened  and  hardened  as  in  scab.  Occasionally 
we  have  outbreaks  of  skin  disease  among  sheep  which  on  super- 
ficial examination  resemble  scab  rather  closely.  These  outbreaks, 
however,  are  due  to  the  awns  of  a  wild  grass  {Stipea  sparta). 
These  spearlike  bodies  gradually  work  their  way  through  the 
wool  into  the  skin,  causing  inflammation  of  the  skin  and  con- 
siderable irritation. 

Treatment 

Suggestions. — Treatent  is  comparatively  easy  where  there  are 
but  few  sheep,  but  it  is  more  difficult  with  large  flocks.  The 
size  of  the  tank,  material  to  be  used,  and  method  of  dipping 
must  depend  upon  the  number  of  sheep,  and  the  accessibility 
and  expense  of  different  materials. 

The  dipping,  as  a  rule,  should  not  be  done  immediately  after 
shearing.  It  is  better  to  wait  a  week  or  ten  days.  Some  good 
may  be  accomplished  without  shearing  if  the  wool  is  parted  by 
hand  and  care  taken  to  get  the  medicine  down  to  the  skin,  but 
it  is  the  usual  experience  that  dipping  unshorn  sheep  is  much 
less  satisfactory. 

The  entire  flock  must  be  dipped,  those  that  are  apparently 
sound  as  well  as  those  that  are  diseased.  And  the  owner  must 
bear  in  mind  that  after  shearing,  the  wool  may  be  a  source  of 
danger,  and  that  it  should  be  so  kept  and  handled  as  to  avoid 
the  possibility  of  reinfection. 

Dipping  is  effective  only  when  it  is  thoroughly  done  and 
properly  repeated.  Lime  and  .sulphur,  coal  tar  dips,  tobacco 
and  arsenic  are  the  various  ingredients  that  are  commonly  used 
in  dipping  for  scab.     The  (luaiitity  of  dip  required  per  sheep 


SHEEP  SCAB  135 

varies  from  two  to  four  gallons,  according  to  the  number  of 
sheep  dipped  and  the  material  used.  Less  dip  is  needed  for 
shorn  than  for  unshorn  sheep. 

It  is  a  good  rule  to  use  any  dip  at  about  100  degrees  F.  Dip- 
ping should  be  repeated  in  10  days,  and  in  some  cases  it  may 
be  necessary  to  give  even  a  third  dipping  after  a  second  inter- 
val of  10  days. 

For  thorough  work  the  entire  flock  should  be  shorn,  then  8  or 
10  days  later  dipped  and  confined  for  another  8  to  10  days  in 
a  place  where  there  have  been  no  scabby  sheep  for  at  least  two 
months.  At  the  close  of  this  period  of  8  to  10  days,  the  flock 
should  be  redipped  and  placed  again  where  there  is  no  danger 
of  infection. 

Dips. — Several  of  the  patent  dips  give  excellent  results,  but 
these  are  usually  more  expensive  than  others  and  are  objection- 
able, inasmuch  as  we  do  not  know  their  composition.  The  fol- 
lowing are  perhaps  as  good  as  any: 

Lime-and-sulphur  dip. — This  is  cheap,  safe,  and  very  effective. 
It  has  given  good  satisfaction  when  made  and  used  according 
to  directions.  Make  this  dip  in  the  following  proportions :  ordi- 
nary sulphur,  24  lbs. ;  unslaked  lime  or  hydrated  lime — but  not 
airslaked — 8  lbs. ;  water,  100  gallons. 

The  lime  and  sulphur  are  placed  in  a  large  kettle  or  other 
suitable  container  with  enough  water  to  slake  the  lime  and  form 
a  paste.  After  the  lime  is  thoroughly  slaked  30  gallons  of 
water  is  added  and  the  mixture  is  boiled  and  stirred  for  3 
hours.  Add  water  to  make  up  to  the  original  30  gallons,  and 
allow  the  solution  to  settle  overnight.  The  liquid  should  then 
be  so  drawn  off  as  to  avoid  stirring  up  the  sediment.  A  spigot 
placed  about  4  inches  from  the  bottom  of  the  barrel  or  tank 
works  nicely. 

For  use,  add  enough  water  to  make  a  total  of  100  gallons. 
The  ooze  or  sediment  is  not  to  be  used  on  the  animal  body,  but 
makes  a  good  disinfectant  for  fences,  pens  and  other  enclos- 
ures. 

Lime  and  sulphur  cannot  be  relied  on  to  kill  sheep  ticks. 
Tobacco  and  sulphur  or  coal-tar  dips  should  be  used  when  there 
are  both  ticks  and  scab. 

Coal-tar  dips. — Certain  dips  of  this  class  are  now  approved  by 
the  Federal  Bureau  of  Animal  Industry  when  used  in  official 
strength  and  directions  followed. 


136  VETERINARY  STUDIES 

Practical  suggestions. — Each  sheep  should  be  kept  in  the  dip 
at  least  two  minutes  by  the  watch,  and  each  sheep  should  go 
under  entirely  at  least  once.  Three  to  five  minutes  are  neces- 
sary for  bad  cases  with  heavy  crusts.  Heavily  pregnant  ew^es 
can  be  safel}'  dipped  if  handled  with  care. 

Ewes,  lambs,  and  bucks  should  be  dipped  in  separate  lots.  It 
is  not  advisable  usually  to  dip  sheep  that  have  recent  wounds 
even  if  the  wounds  are  small  unless  they  are  nearly  healed.  Al- 
ways water  and  feed  well  within  three  to  five  hours  before  dip- 
ping. Soft  water  makes  the  best  dip.  The  solution  should  be 
from  40  to  48  inches  deep,  with  an  allowance  made  for  each 
sheep  to  carry  out  in  the  wool,  two  quarts  to  two  gallons,  depend- 
ing on  the  wool. 

Drowning  and  other  accidents  can  be  avoided  by  watchful 
care.     Lambs  may  be  dipped  at  about  one  month  old. 

In  using  any  dip  no  matter  if  proprietary  or  homemade,  fol- 
low directions  exactly.  It  is  not  uncommon  for  stockmen  to 
have  unsatisfactory  results  from  the  use  of  well-recognized  dips, 
usually  because  they  try  the  dip  a  little  weaker  than  the  direc- 
tions call  for,  or  because  they  were  a  little  careless  and  hurried 
the  sheep  through  the  dipping  vat  too  rapidly,  or  by  returning 
the  sheep  after  dipping  to  infected  pastures  or  yards. 

For  a  small  flock  the  portable  galvanized  vats  are  very  con- 
venient. There  should  be  at  least  one  drainage  pen  with  floor 
to  carry  the  dip  from  the  dripping  sheep  back  to  the  vat.  Two 
such  pens  are  a  great  convenience. 

Disinfectwn. — All  structures,  sheds,  pens,  posts,  etc.,  that  may 
have  been  contaminated  should  be  cleaned  and  well  disinfected 
unless  sheep  can  be  kept  away  from  them  for  a  long  period,  as 
previously  indicated. 

Any  good  dip  should  make  also  a  good  disinfectant  for  this 
use.  In  case  a  lime-and-sulphur  dip  is  selected,  then  the  "ooze" 
or  sediment  which  will  otherwise  be  discarded  may  be  used. 
Plowing  or  burning  over  ground  makes  it  safe. 


LECTURE  XXVII 
MANGE 


Horse  IMange 

Causes. — flange  of  horses,  cattle,  hogs  and  many  other  ani- 
mals is  similar  in  cause,  symptoms,  and  spread  to  sheep  seal). 
Horses,  like  sheep,  are  subject  to  three  forms  of  the  disease.  The 
most  common  form  in  the  horse  is  due  to  the  Sarcoptes,  Avhich 
burrows  and  affects  the  head,  neck,  and  body.  Another  form  is 
due  to  Psoroptes  "svhich  moves  freely  and  affects  the  surface.  A 
third  form  is  due  to  the  Chorioptes,  which  lives  on  1lie  surface, 
moves  but  little,  and  affects  feet  and 
legs,  usually  below  the  knees  and 
hocks. 

Sarcoptes  scahei  var.  cqui  is  a 
common  cause  of  horse  mange.  This 
is  one  of  the  smaller  mites,  practi- 
cally invisible  to  the  unaided  eye. 
These  mites  burrow  tunnels  into 
and  under  the  skin.  The  eggs  are 
laid  and  the  young  are  hatched  in 
these  tunnels.  On  account  of  this 
tunneling  habit,  spread  is  slow  at 
first  and  the  disease  difficult  to 
cure  in  advanced  cases. 

Spread  of  mange  mites  may  be  direct  from  horse  to  horse  or 
indirect  by  way  of  the  harness,  saddle,  blanket,  currycomb, 
or  a  post,  for  example. 

Symptoms. — The  disease  usually  appears  first  on  the  head  or 
side  of  the  neck,  and  the  first  symptoms  are  small  pimples  and 
itching.  The  skin  loses  hair,  becoming  thickened,  roughened, 
and  wrinkled.  Affected  horses  are  much  more  uneasy  at  night, 
particularly  in  a  warm  stable. 

Treatment. — It  is  usually  necessary  to  repeat  treatment  at 
least  once,  and  in  bad  cases,  several  times  at  intervals  of  ten 

137 


Fig.  46. — Mange  Mite. 

The  cause  of  one  form  of 
horse  mange.  Psoroptes  com- 
munis equi. 


138  VETERINARY  STUDIES 

days.    Treat  all  horses  that  have  been  exposed  to  infection,  and 
watch  closely  for  reappearance  of  the  disease. 

If  the  horses  are  halter  broken  and  conditions  permit,  clip 
the  hair  and  burn  it.  Soften  the  scabs  and  crusts  by  a  thor- 
ough application  of  soft  soap  well  rubbed  in  over  the  affected 
surface.  The  soap  is  left  on  for  two  or  three  hours  and  then 
washed  off.  The  scab  should  then  be  very  easy  to  remove.  Allow 
the  skin  to  dry  and  apply  one  of  the  following  treatments. 

Cattle  Mange   (Barn  Itch) 

This  is  the  same  general  disease  as  horse  mange  and  sheep 
scab.  Mange  causes  serious  trouble  and  losses  in  range  cattle 
and  is  occasionally  a  source  of  serious  trouble  among  farm 
herds.  Breeding  herds  seem  most  apt  to  become  affected  on 
account  of  the  most  frequent  opportunities  for  introducing  it 
by  the  purchase  of  new  breeding  stock.  This  disease  is  rarely 
fatal  in  cattle  that  are  well  kept ;  but  is  a  source  of  financial 
losses  by  reason  of  unthrift.  In  farm  herds  it  is  a  serious 
nuisance,  and  should  not  be  neglected  or  ignored. 

Cause. — In  cattle  there  are  four  types  due  to  Sarcoptes, 
Psoroptes,  and  Chorioptes  and  Demodex. 

The  Sarcoptes  (burrowing)  affect  especially  the  inside  of  the 
thigh,  root  of  tail,  under  surface  of  the  neck  and  the  brisket. 
The  Chorioptes  affect  chiefly  the  tail  and  legs.  This  form  is 
slow,  local  and  much  less  important  than  Psoroptes.  Demodex 
causes  small  lumps  on  neck  and  shoulders  from  millet  to  pea 
size.  It  is  rare  and  practically  incurable.  The  Psoroptes  is 
most  common.  This  form  affects  the  general  body  surface,  and 
spreads  rapidly.  It  lives  upon  the  surface  of  the  body  and  can 
move  about  rather  freely ;  hence  the  disease  spreads  more  rapidly 
than  the  common  mange  and  is  easier  to  cure.  The  skin  irrita- 
tion and  inflammation  is  due  to  punctures  which  the  mites 
make  in  order  to  suck  their  nourishment. 

Symptoms. — Symptoms  of  cattle  mange  are  similar  in  a  gen- 
eral way  to  those  shown  in  sheep  scab  and  mange  of  horses. 
With  cattle,  the  disease  usually  appears  first  on  the  neck  or 
shoulder  or  near  the  tail,  and  from  these  places  is  spread  over 
other  portions  of  the  body.  The  skin  becomes  bald,  thickened 
and  wrinkled  and  perhaps  badly  scratched  and  sore  as  a  result 
of  rubbing. 


MANGE  139 

There  may  be  very  little  to  show  for  mange  while  the  cattle 
are  out  on  grass  and  doing  well,  although  the  mites  are  still 
present  on  the  body.  Fall,  winter,  and  early  spring  are  the 
seasons  of  greatest  prevalence  and  annoyance. 

Treatment 

Cattle  and  horses  may  be  either  dipped  ^  like  sheep  or  treated 
with  local  applications  according  to  the  extent  of  the  disease 
and  number  of  animals  affected.  Dipping  is  more  thorough 
and  reliable.  It  may  be  done  either  in  a  long  swimming  tank, 
or  the  animals  may  be  dipped  one  at  a  time  in  a  dipping  cage. 

All  exposed  animals  and  every  portion  of  their  body  surface 
should  be  treated  either  by  wash  or  dip.  In  case  of  dipping, 
all  portions  of  the  body  should  go  under  the  dip  at  least  once 
and  the  animal  should  be  kept  in  the  dip  from  two  to  four 
minutes.  Treatment  should  be  repeated  in  seven  to  ten  days. 
If  mange  persists,  after  two  good  dippings,  apply  the  treatment 
for  Sarcoptic  mange.  In  case  of  infected  herds,  dipping  should 
be  repeated  twice  each  spring  and  fall  until  the  disease  is 
entirely  removed.  The  dip  should  be  quite  warm,  100  to  105 
degrees  F. 

Stock  must  not  be  hungry  or  thirsty  when  dipped ;  they 
should  be  fed  and  watered  two  to  four  hours  before  dipping. 
It  is  also  important  that  stock  be  not  heated,  as  by  driving  fast 
before  dipping.     Let  them  cool  off  first. 

After  treatment,  the  stock  should  not  be  put  back  into  in- 
fected yards,  pens,  or  stables.  Such  enclosures  should  be  either 
thoroughly  disinfected  or  the  stock  should  be  kept  out  of  them 
for  a  considerable  period. 

Almost  any  oil  when  freely  used  on  horses  is  liable  to  cause 
temporary  loss  of  the  hair. 

(a)  Creosote,  diluted  with  any  non-irritating  oil,  1  to  16, 
and  iLsed  by  hand  application  for  small  areas, — never  for  areas 
covering  more  than  one  half  of  the  body  at  one  time. 

(&)      Creosote,  1;  oil  of  tar,  10;  soft  soap,  10;  use  like   (a). 

(c)  Lime  and  sidphiir  dip  is  an  old,  thoroughly  tried  and 
reliable  treatment  which  is  cheap,  effective,  and  safe.     Direc- 

'  For  detailed  information,  concerning  dipping  plants,  see  Nebraska 
Station  Bulletin  74,  North  Dakota  Station,  Bulletin  No.  61,  or  Bureau  of 
Animal  Industry,  Bulletin  1017. 


140  VETERINARY  STUDIES 

tions  should  be  followed  closely  as  given  under  Sheep  Scab 
Lect.  XXVI.  This  dip  is  prepared  as  for  sheep  except  that  we 
use  twelve  pounds  of  lime  instead  of  eight  pounds. 

Always  treat  the  apparently  healthy  skin  to  a  considerable 
distance  beyond  the  diseased  border  in  case  of  small  areas  and 
local  treatment. 

Prognosis. — The  prospect  of  recovery  is  good  in  recent  cases, 
but  if  the  animal  has  been  long  and  badly  affected  and  the 
disease  covers  a  considerable  portion  of  the  body,  then  the  pros- 
pect is  not  encouraging.  The  Sarcoptic  horse  mange  is  much 
harder  to  cure  than  common  body  scab  of  cattle,  and  may  re- 
quire three  to  five  dippings  at  six  to  ten  day  periods,  depend- 
ing on  the  weather. 

Disinfection. — All  structures  which  may  have  become  con- 
taminated should  be  thoroughly  cleaned  and  disinfected.  The 
ooze  or  sediment  made  in  the  preparation  of  lime  sulphur  dip 
will  serve  w^ell  for  this  purpose,  or  a  6  per  cent  solution  of  any 
of  the  better  coal-tar  disinfectants  may  serve  the  same  purpose. 


LECTURE  XXVIII 

INTERNAL  PARASITES 

INIany  kinds  of  internal  parasites  seriously  affect  the  various 
classes  of  stock.  The  few  selected  illustrations  used  here  for 
the  horse  and  sheep  can  give  only  o'eiieral  information  on  th;^ 
subject.  Space  does  not  permit  of  detailed  information  con- 
cerning even  those  parasites  selected  for  discussion.  Losses  in 
sheep  from  parasites,  internal  and  external,  are  especially  im- 
portant, and,  as  a  rule,  they  are  jireventable. 

Bots. — The  common  hot  of  the  horse's  stomach  is  the  larva 
form  of  the  horse  gadfly  or  bot  fly,  Gastrophiliis  intcsiinalis 
(equi).  This  fly  is  commonly  observed  buzzing  around  horses  in 
the  summer  and  early  fall.  It  is 
about  the  size  of  a  common  honey  ^^ 
bee.  The  bot  fly  reproduces  by  ^^ 
oval,  light  yellow  eggs,  which  are  ^^ 
attached  by  the  adult  fly  to  hairs       W^ 

about   the    neck,   breast,    and   fore-        ^^ 

rjpj-f^g  Fig.  47. — Horse  Bot  Fly  and 

In  due  time,  the  eggs  hatch  and 
the    small    larva    or    bots    escape.      „„,,•,,  e,^„^.    L^rva  in  the  third 
Some  are  licked  off,  burrow  into  the      stage, 
mucous  membrane  of  the  lips  for  a 

few  days,  then  escape  and  make  their  way  to  the  stomach  where 
they  firmly  attach  themselves  to  the  lining  by  small  hooks.  They 
remain  thus  in  the  stomach  about  10  months,  f  nally  passing  off 
with  manure.  The  next,  or  pupal  stage,  lasts  from  four  to  six 
weeks,  and  is  passed  in  manure  or  in  the  ground.  After  this 
stage  the  mature  fly  appears,  ready  for  the  next  generation. 

Another  species,  Gastrophiliis  nasalis,  locates  in  the  horse's 
nasal  chamber.  A  third  species  Gastrophiliis  hemorrJioidalis  lo- 
cates in  the  rectum,  and  causing  intense  itching  at  times.  These 
parasites  may  be  removed  by  free  rectal  injections  of  0.5  per 
cent  creolin. 

Bots  rarely  do  any  serious  harm,  although  they  are  very  com- 
mon,    ^ledical  treatment  by  the  use  of  carbon  bisulphide    (6 

141 


142 


VETERINARY  STUDIES 


drams  in  capsules)  is  quite  satisfactory.  No  food  should  be 
allowed  during  twenty-four  hours  before  treatment.  Four  to 
six  hours  after  treatment  an  oil  physic,  such  as  raw  linseed  oil, 
should  be  given.  It  is  usually  advisable  to  have  this  treatment 
given  by  a  veterinarian. 

Nematodes  (round  worms). — For  pin  worms  {Oxyuris  equi) 
which  inhabit  the  rectums  of  horses,  empty  this  organ  by  means 


Fig.  48. — Horse  Bots  and  Bot  Fly. 
(B.  A.  I.) 

The  eggs  are  deposited  on  the  hairs  during 
the  fall.  They  are  taken  off  by  the  tongue ; 
hatch,  and  develop  mainly  in  the  stomach, 
into  the  bots   (larvae). 


of  w-arm  water  injections,  and  then  u>se  I/2  gallon  of  warm  rectal 
injections  of  astringent  and  bitter  medicine,  like  a  very  mild 
solution  of  copperas  or  0.5  per  cent  creolin  or  a  strong  tea 
made  of  quassia  chips. ^  Repeat  once  daily  for  two  or  three 
days  and  follow  with  an  oily  physic,  e.g.,  one  quart  of  raw  lin- 
seed oil. 

Ascaris  equi. — For  the  "long  white  worms"  6  to  12  inches 
long,  affecting  the  small  intestine  of  horses,  the  treatment  must 
be  vigorous  and  continued. 

Give  a  cathartic  of  1  quart  linseed  oil.  Feed  little  or  no  hay 
for  4  days.  Fast  12  hours,  then  give  1  to  4  ounces  of  turpentine 
in  from  1  pint  to  1  quart  of  raw  linseed  oil  on  the  5th  day,  and 

^  A  large  handful  of  quassia  chips  in  two  quarts  of  ■wuter.  Steep  15 
minutes  and  let  stand  overnight. 


INTERNAL  PARASITES  143 

repeat  on  the  6th.  Beginning  on  the  sixteenth  day  repeat  this 
whole  process,  if  the  first  treatment  does  not  seem  entirely  effec- 
tive.    Always  use  raw  linseed  oil. 

A  second  method  of  treatment  is  as  follows :  After  giving  the 
preparatory  treatment  described  above,  give  tartar  emetic,  1  to 
3  drams  depending  on  the  size  and  the  age  of  the  animal,  mix- 
ing the  medicine  with  a  small,  damp  feed  of  oats  or  grain. 
Repeat  in  12  hours.    Keep  the  horse  quiet  and  empty. 

Strong yles. — These  are  also  round  worms  (Nematodes).  The 
horse  is  affected  especially  by  four  species. 

In  general  the  mature  worm  inhabits  the  cecum  and  the  colon. 
The  eggs  are  deposited,  then  pass  off  with  the  manure  and  hatch. 
The  embryo  worms  are  taken  in  by  the  future  host  with  water 
or  feed.  Some  of  the  immature  worms  pass  through  the  intes- 
tinal mucous  membrane  and  into  the  blood  vessels  of  the  abdomi- 
nal organs — the  intestines  for  instance,  where  they  are  likely  to 
indirectly  cause  colic  and  serious  disease  of  the  bowel,  by  ob- 
structing circulation. 

The  symptoms  are  variable  and  not  diagnostic.  There  are  evi- 
dences of  intestinal  irritation  like  diarrhea,  recurrent  colic, 
unthrift  and  variable  appetite,  usually  lack  of  appetite. 

Treatment  for  the  strongyle  infection  in  horses  is  satisfactory 
if  given  in  time.  Best  results  are  secured  from  oil  of  chcno- 
podium.  The  horse  is  allowed  no  feed  for  36  hours,  then  is 
given  about  4  drams  of  this  oil  in  a  quart  of  raw  linseed  oil. 

For  the  common  round  worms  in  hogs,  no  food  is  given  to  the 
hog  for  from  8  to  24  hours.  Then  when  the  hog  is  hungry  and 
emjjty,  he  is  given  one  to  3  teaspoonfuls  of  turpentine,  accord- 
ing to  size  and  age,  diluted  about  ten  times  in  skimmed  milk  or 
thin  slop.  This  dose  is  repeated  daily  for  several  days,  and  then 
a  physic  is  given. 

Oil  of  chenopodium,  about  45  drops  in  1  ounce  of  castor  oil 
per  IDO  i)ounds  weight,  is  also  very  effective — especially  when 
properly  repeated. 

Tapeworms  or  taenia  (flatworms). — These  are  especially  seri- 
ous in  sheep,  which  are  infested  by  several  species.  Three  kinds 
are  common  to  cattle,  sheep  and  goats.  The  life  history  of  tape- 
worms is  vtM-y  significant.  Taenia  are  two-host  parasites.  They 
pass  the  larval  stage  in  one  host  as  bladder-like  cysts,  and  their 
adult  form  in  another  species  of  host  as  a  flat,  ribbon-like  body 
of  many  short  segments.  For  example,  the  sheep  disease  known 
as  gid  is  caused  by  the  bladder  worm  larva  of  a  tapeworm  which 


144 


VETERINARY  STUDIES 


is  adult  in  the  dog.     A  common  adult  tapeworm  of  the  human, 
has  its  larval  or  cyst  stage  in  the  flesh  of  the  hog,  causing  what 

is  called  "measly  pork." 

The  adult  tapeworm  constantly 
forms  new  segments  back  of  the 
small  head.  These  segments  ma- 
ture while  new  segments  are  being 
added  in  front  of  them.  The 
terminal  segments,  filled  with  eggs, 
separate  and  pass  off  with  the 
manure,  while  the  head  remains 
attached  to  the  mucous  membrane 
and  continues  to  produce  new 
segments. 

The  injury  to  the  host  may  be 
great  or  slight  depending  on  the 
location — usually  in  the  intestine 
— and  number  of  worms.  The 
worms  may  impair  intestinal 
(capacity  and  function  by  mere 
I)resence  in  large  numbers.  They 
may  enter  bile  ducts  and  cause 
serious  trouble.  Some  species  have 
heads  armed  Avith  hooks  which 
irritate  the  intestine  and  thus  im- 
pair digestion  and  absorption. 
They  may  produce  and  free  to  the 


Fig.  49. — A  Common  Tapeworm 

OF  Sheep  (Curtice.) 

Taenia  expansa, 

1,  Hjead  and  neck;  A,  A, 
suckers;  B,  B,  folds  in  neck; 
C,  C,  first  segments. 

2.  Head  and  body,  showing 
segments.     A,  head. 

intestinal  contents,  toxins  or  poi- 
sons. The  cyst  stage  may  seriously  disturb  the  invaded  host 
organ,  e.g.,  the  brain  as  in  gid. 

Treatment  ^  can  be  useful  only  when  given  before  weakness 
begins.  Preparation  for  treatment  is  most  important.  Allow 
no  dry  bulky  food  for  several  days.  Fast  12  to  24  hours,  depend- 
ing on  age  and  previous  feed.  Then  give  1  to  2  drams  freshly 
ground  areca  nut  in  a  small  feed  such  as  damp  bran,  or  in  a 
small  quantity  of  thin  sirup,  so  that  each  sheep  gets  its  proper 
dose.  Copper  sulphate  used  as  for  stomach  worms  (see  Lee- 
ture  XXX)  is  also  a  satisfactory  treatment,  and  may  be  used 
for  both  parasites  at  the  same  time.  Follow  this  treatment  in 
3  or  4  hours  by  a  physic. 

^  For  sheep.     Dose  varies  greatly  with  age  and  weight. 


LECTURE  XXIX 
NODULE  DISEASE  OF  SHEEP 

General  history. — The  history  of  outbreaks  is  often  as  fol- 
lows: Sheep  have  access  during  the  summer  and  fall  to  low 
pastures  or  pond  or  well  water  that  receives  drainage  from  a 
sheep  yard  or  pasture.  Perhaps  the  grass  was  short  and  the  tloek 
was  compelled  to  graze  very  close.  During  the  winter  the  fiock 
becomes  unthrifty;  some  individuals  grow  thinner  and  weaker 
and  a  number  die.  A  dead  sheep  is  opened  and  the  intestines 
show  on  the  surface  a  large  number  of  nodules  about  the  size 
of  garden  peas,  Avhicli  are  most  common  on  the  large  intestine. 
As  soon  as  grass  comes  and  the  sheep  are  turned  out  they  begin 
to  do  better,  and  the  disease  seems  to  disappear. 

Cause. — The  disease  is  caused  by  a  minute  roundworm.  Sheep 
are  affected  by  two  species  but  OcsopJiagostomum  columhianum 
is  the  common  species.^  The  adult  worms  are  about  three  quar- 
ters of  an  inch  in  length  and  inhabit  the  intestines.  The  imma- 
ture forms  vary  from  one  hundredth  to  one  sixth  of  an  inch  in 
length,  depending  on  development,  and  exist  inside  of  the  little 
nodules  which  constitute  the  most  prominent  features  of  the 
disease  as  seen  on  examination  post  mortem. 

There  is  some  question  concerning  the  life  history,  but  the 
eggs  are  apparently  laid  by  the  adult  female  in  the  intestine 
and  as  eggs  or  embryos  pass  out  with  manure,  hatch  outside, 
and  gain  entrance  as  embryos.  The  embryo  worms  find  their 
way  through  the  internal  lining  of  the  intestine,  and  locate  in 
the  bowel  wall.^  Here  they  give  rise  as  foreign  bodies  to  the 
little  tumors  or  nodules,  about  the  size  of  a  pea,  which  nature 
throws  around  them,  evidently  in  an  attempt  to  fence  them  in. 
They  cause  irritation  as  foreign  bodies,  and  this  irritation  will 
account  for  the  little  tumors  which  are  found  on  the  side  of  the 

*  Cattle  and  hogs  have  each  one  species  of  nodule  worm  wliich  does  not 
affect  sheep.     In  these  the  loss  is  unimportant. 

^Diniock  has  found  evidence  which  indicates  that  the  eggs  may  be  de- 
posited within  the  intestinal  mucous  membrane  and  there  hatch  the  em- 
bryo worms. 

145 


146  VETERINARY  STUDIES 

intestine ;  i.e.,  the  nodules.  The  contents  of  these  nodules  is 
usually  chees}^,  and  greenish  or  yellowish  in  color. 

Later  the  young  worms  leave  the  nodules  and  mature  in  the 
intestinal  canal. 

Some  of  the  eggs  and  adult  worms  pass  out  with  the  manure, 
and  thus  infect  the  pastures  and  feed  yards,  ponds,  or  sluggish 
streams  which  receive  their  drainage. 


Fig.  50. — Nodule  Disease.     (M.  H.  E.) 
Intestines  of  sheep. 

Injury  done. — The  extent  of  injury  to  the  individual  sheep 
depends  mainly  upon  the  number  of  worms  present,  and  the  con- 
dition of  the  sheep  as  to  vitality  and  resisting  power.  There 
may  be  something  of  an  inflammation  of  the  bowels  while  the 
young  worms  are  passing  through  the  lining  of  the  intestine, 
but  the  main  injury  is  that  of  starvation.  So  large  a  portion  of 
the  bowel  is  affected  by  the  parasites  when  they  are  present  in 
great  number  that  there  is  not  enough  healthy  tissue  for  ab- 
sorption of  food  material.  It  may  be,  also,  that  the  worms  ex- 
crete poisonous  substances;  or  their  presence  may  lead  indi- 
rectly to  the  formation  of  poisonous  materials  which  are  ab- 
sorbed.    A  badly  infested  sheep  may  have  plenty  of  good  food 


NODULE  DISEASE  OF  SHEEI  147 

and  yet  be  too  weak  to  eat  it,  or  if  able  to  eat,  he  may  still  be 
starving-  becanse  the  intestinal  wall  cannot  take  up  the  food 
that  may  be  ready  for  absorption. 

Diagnosis. — This  disease  is  rather  common  among  farm  sheep. 
There  is  diarrhea,  debility,  pallor  of  mucous  membranes,  and 
emaciation.  Diagnosis  can  only  be  made  certain  by  finding  the 
characteristic  nodules  in  an  examination  of  the  dead  animal, 
for  sheep  infested  with  some  other  parasitic  diseases  show  simi- 
lar symptoms  and  conditions  during  life. 

Treatment. — It  is  probable  that  but  little  can  be  accomplished 
by  medical  treatment,  because  the  worms,  during  a  large  part 
of  their  life  history,  are  walled  up  in  these  nodules  and  beyond 
the  reach  of  any  medical  agent. 

It  is  possible  that  worm-destroying  medicines,  like  those  rec- 
ommended for  stomach  worms,  if  frequently  repeated  during 
the  summer,  might  prove  both  curative  and  preventive,  by  kill- 
ing the  adult  worms,  which  live  free  in  the  intestine.  Pasture 
infection  may  be  destroyed  by  plowing  and  cropping  one  season. 
Dr.  Dahymple  and  others  have  shown  that  lambs  may  suckle 
the  diseased  dams  under  certain  conditions  and  usually  remain 
free  from  infection.  This  is  accomplished  by  what  is  known  as 
the  bare-lot  method.  Under  this  system  lambs  are  not  allowed 
access  to  any  pasture  that  can  possibly  have  been  contaminated 
by  the  older  sheep. 

The  bare-lot  method  provides  that  ewes  and  lambs  must  be 
kept  in  a  lot  that  is  bare  of  any  grass  or  weeds  which  sheep  may 
eat.  This  lot  must  be  rather  smooth  and  must  drain  promptly, 
without  standing  pools  after  rain.  No  grazing  for  the  older 
sheep  is  permitted,  the  flock  being  fed  on  soiling  crops  and  what- 
ever gi'ain  may  be  necessary.  Fresh,  clean  water  must  be  pro- 
vided. Food  and  water  must  be  given  in  such  a  way  that  they 
cannot  possibly  be  contaminated  from  the  ground ;  food  that 
falls  out  of  the  racks  must  be  raked  up  rather  frequently. 

Ewe  lambs  to  be  kept  in  the  flock  should  be  raised  with  spe- 
cial care  to  avoid  trouble  the  next  season  from  chance  infection 
tliat  occurs  to  sucli  lambs  from  the  bare  lot.  By  this  metliod 
the  lambs  may  run  with  the  diseased  ewes  until  weaning  time 
with  comparatively  slight  risk  of  infection.  In  dealing  with  a 
serious  outbreak  of  this  disease  it  should  be  remembered  that 
infested  flocks  usually  do  fairly  well  during  the  summer  and 
early  fall  montlos.     If  a  flock  is  badly  infested  with  nodule 


148  VETERINARY  STUDIES 

disease,  it  will  generally  prove  good  management  to  nurse  the 
flock  through  until  spring,  then  depend  on  getting  the  sheep 
into  shape  for  market  during  the  summer,  and  sell  out  for 
butcher  stock  in  the  early  fall.  Such  sheep  are  entirely  fit  for 
food  purposes  when  in  good  flesh. 

Prevention. — New  sheep  should  be  purchased  from  a  flock 
that  has  been  thrifty  during  two  previous  late  winters  and  early 
springs,  and  they  should  be  kept  for  two  seasons  on  some  other 
pasture  than  the  one  previously  used  on  the  infected  farm.  It 
will  be  better  still  if  the  flock  can  be  kept  part  of  the  season  on 
pasture  and  part  of  the  season  on  plowed  crops;  e.g.,  rape, 
sorghum,  field  peas,  or  meadow  land  that  has  not  recently  been 
used  for  sheep  pasture.  The  new  flock  must  not  be  allowed  to 
drink  from  any  pond  or  sluggish  stream  that  has  received  drain- 
age from  the  infested  pasture  or  barnyard. 

With  a  view  to  preventing  this  and  other  parasitic  diseases, 
the  flock  should  not  be  kept  too  long  on  one  pasture,  but  should 
be  moved  from  pasture  to  pasture;  and  from  pasture  to  stubble 
fields,  cut-over  meadow,  rape,  etc.  Sluggish  streams  and  ponds 
should  always  be  regarded  with  suspicion. 

It  is  possible  to  practically  rid  a  flock  from  the  nodule  disease 
by  following  this  course  of  shifting  the  flock  about  for  several 
years,  plowing  up  pastures  occasionally,  and  using  plowed 
crops.  The  infectiousness  of  pastures  has  been  shown  by  care- 
ful experiment  in  which  infected  sheep  were  placed  on  small 
pastures  during  a  season  and  then  during  the  next  season  sheep 
were  kept  on  this  same  pasture  which  were  previously  free  from 
nodule  disease.  Rapid  infection  of  the  second  flock  was  secured 
in  this  way.  The  disease  spreads  from  ewes  to  pasture  and  from 
pasture  to  lamb. 


LECTURE  XXX 


STOMACH  WORMS   (SHEEP) 

The  stomach  -worm  is  an  especially  common  and  serious  para- 
site of  sheep,  and  this  means  much,  for  parasitic  diseases  of 
sheep  are  the  serious  ones.  This  ])arasite  is  very  widespread 
especially  in  permanent  grass  pastures.  It  affects  sheep  of  all 
ages  and  young  cattle,  but  especially 
lambs.  Older  sheep  showing  no  symp- 
toms are  the  ones  usually  to  blame  for 
spreading  the  disease. 

The  parasite  {Hoemonchus  contor- 
tus)  which  causes  this  trouble  is  a 
small,  threadlike  worm,  perhaps  an 
inch  in  length  and  so  slender  that  it 
must  be  looked  for  carefully  or  one  is 
liable  to  miss  it.  The  individual 
worms  are  somewhat  twisted  and  are 
found  in  the  fourth  stomach.  Fre- 
quently they  are  in  motion.  If  they 
are  present  in  great  numbers,  the 
stomach  contents  near  the  mucous 
membrane  may  seem  to  be  fairly  alive 
and  s(iuirming.  The  Avorms  vary 
from   reddish  to  dirty  white  in  color. 

Life  history. — Tliis  parasite  is  pres- 
ent  in  the  stomach  at  all  times  of  the 


'ii;.  .'a. 

Embryo  of  Ila'tnonclius 
contortus  coiled  on  tip  of 
grass  blailo.  Enlarged  100 
times.  (Ransom,  B.  A.  1., 
Circular  93.) 


year. 

The  eggs  are  passed  off  in  the  feces, 
hatch  in  14  to  24  hours  in  warm 
weather,  and  reach  tlie  ensheathed 
embi-yo  stage  in  from  ten  days  to  two 

weeks  when  conditions  of  temperature  and  moisture  are  suit- 
able. Eggs  and  newly  hatched  emliryos  are  very  sensitive  to 
freezing  or  drying,  and  easily  die  under  these  conditions.  En- 
sheathed embryos  are  wry  resistant.     We  cannot   depend  on 

149 


]50  VETERINARY  STUDIES 

their  natural  destruction  in  much  less  than  a  year.  They  have 
been  shown  to  be  capable  of  infection  after  several  months. 

When  the  atmosphere  is  moist,  embryos  leave  the  manure 
or  earth  and  crawl  up  the  moistened  blades  of  grass  or  similar 
objects,  climbing  only  while  there  is  moisture.  If  now  they  are 
swallowed  by  a  suitable  host,  the  embryo  continues  develop- 
ment for  about  three  weeks,  at  which  time  the  females  may 
begin   to   produce   eggs. 

Symptoms. — There  are  no  diagnostic  symptoms  by  which  this 
disease  can  be  distinguished  from  other  internal  parasitic  dis- 
eases of  sheep.  There  is  a  gradually  developing  dullness,  weak- 
ness, and  unthrift.  Lambs  are  affected  more  seriously  than 
older  sheep.  These  are  usually  unthrifty  during  the  late  sum- 
mer, and  some  die  during  the  late  summer  and  fall.  The  most 
common  and  evident  symptoms  are  pallor,  loss  of  flesh,  and 
weakness.  The  appetite  is  variable;  affected  sheep  are  usually 
dull,  listless,  and  often  have  unusual  thirst  and  diarrhea.  There 
frequently  appear  swellings  under  the  jaw. 

To  make  a  certain  diagnosis  it  is  usually  necessary  to  ex- 
amine the  carcass  of  sheep  recently  dead  or  kill  a  sick  one  for 
this  purpose.  Examine  very  carefully  the  fourth  stomach.  If 
this  stomach  is  opened  at  the  top  and  contents  allowed  to  rest 
quietly,  the  stomach  worms,  if  present  in  sufficient  numbers  to 
cause  trouble,  will  be  seen  in  quite  active  motion,  wiggling  about 
like  tiny  snakes.  They  may  sometimes  be  found  in  very  large 
numbers  close  to  the  lining  membrane  as  slender  reddish  worms 
varying  from  one  half  to  about  one  inch  in  length.  If  the 
fourth  stomach  be  emptied  and  the  worms  are  present  in  large 
numbers,  some  may  be  seen  attached  to  the  mucous  mem- 
brane. 

Management  of  infected  flocks. — An  infected  pasture  may  be 
safe  after  a  year  if  there  has  been  no  use  by  sheep  in  the  inter- 
val. Burning  over  a  pasture  is  very  efficient  for  the  ground 
actually  burned  over.  A  pasture  that  has  been  plowed  and 
cropped  one  season  is  usually  safe.  Freezing  kills  eggs  and 
early  stage  embryos. 

In  dealing  with  an  infected  flock,  we  may  treat  both  the  lambs 
and  their  mothers,  beginning  with  the  ewes  early  in  the  season 
before  the  lambs  are  old  enough  to  treat.  The  death  loss  may 
thus  be  prevented  and  the  lambs  do  much  better.  It  should  be 
clear  that  there  is  no  way  of  rapidly  eradicating  stomach  worms 


STOMACH  WORMS  (SHEEP)  151 

from  a  diseased  flock.     The  rational  hope  lies  in  reduction  and 
gradual  eradication. 

Low,  wet  pastures  are  to  be  avoided.  Hillside  pastures  are 
much  safer  so  far  as  internal  parasites  are  concerned;  and  if 
possible  permanent  pastures  for  sheep  should  not  be  used  on 
account  of  danger  from  many  kinds  of  internal  parasites.  Fre- 
quent changes  of  grazing  ground  are  desirable  for  any  flock,  and 
especially  one  infested  with  internal  parasites.  In  case  of 
stomach  worms,  the  flock  should  move  every  two  or  three  weeks 
on  pastures,  meadows,  fields,  sowed  crops,  etc. 

Medical  treatment. — Sheep  intended  for  medical  treatment 
should  have  no  feed  during  12  to  24  hours  before  the  medicine 
is  given.  No  matter  which  treatment  is  to  be  given,  it  should 
be  tried  on  a  few  sheep  before  treating  a  very  large  number. 

The  Bureau  of  Animal  Industry  has  done  some  careful  ex- 
perimenting in  this  line,  and  recommends  coal-tar  creosote  as  a 
satisfactory  treatment.  This  medicine  is  not  expensive  and  is 
very  easily  obtained  and  prepared  but  variable  in  quality.  It 
is  important  to  insist  upon  getting  coal-tar  creosote. 

If  reliable  coal  tar  creosote  can  be  secured  give  as  a  1  per 
cent  solution;  that  is,  1  ounce  of  the  creosote  to  99  ounces  of 
water  in  doses  proportioned  to  the  age  and  size  of  the  sheep. 
Lambs  4  months  old  take  2  to  4  ounces;  older  sheep  take  3  to 
5  ounces.  If  there  is  any  reason  to  suspect  the  presence  of 
worms  in  the  intestines,  then  thymol  should  be  added  to  the 
creosote  treatment.  The  dose  of  thymol  is  from  30  to  100 
grains.  Each  dose  of  thymol  is  to  be  added  to  the  dose  of  creo- 
sote after  the  latter  has  been  mixed  and  measured,  and  should 
then  be  given  immediately.  Only  fresh  crystallized  thymol 
should  be  accepted, 

Bluestone  (copper  sulphate)  has  been  accepted  as  one  of  the 
most  satisfactory  treatments  for  tliis  trouble,  but  it  needs  to  be 
given  in  carefully  regulated  doses.  Best  results  are  secured 
from  repeated  doses  every  4  to  6  weeks,  from  spring  till  frost. 
This  medicine  may  be  made  up  as  follows:  Dissolve  1  pound 
(avoirdupois)  of  fresh  powdered  bluestone  in  12  gallons  of 
water.  For  this  treatment  the  animal  must  be  kept  off  feed 
from  20  to  24  hours.  The  dose  for  a  lamb  6  months  old  is  40 
CO.;  sheep  12  months  old,  60  c.c.  (about  2  ounces)  ;  18  months, 
80  c.c.;  2  years  90  to  100  c.c. ;  calves  2  to  3  months  old  take 
about  100  c.c.     When  the  bluestone  treatment  is  used,  sheep 


152  VETERINARY  STUDIES 

should  receive  no  water  on  the  day  that  they  are  treated,  either 
before  or  after  treatment.  For  the  first  treatment  of  a  badly 
infected  flock,  repeat  once  or  even  twice  at  ten-day  intervals. 
Treatment  is  easily  given  with  a  metal  dose  syringe. 

Drenching  sheep. — For  giving  medicine  to  sheep,  a  drenching 
tube  should  be  used,  or  a  metal  dose  syringe,  or  a  long-necked 
bottle.  A  very  satisfactory  drenching  tube  may  be  easily  made 
with  an  ordinary  tin  funnel,  which  is  inserted  into  one  end  of 
a  rubber  hose  about  3  feet  long  and  about  one  half  inch  in 
diameter.  A  piece  of  brass  or  iron  tubing  4  to  6  inches  long  is 
inserted  into  the  other  end  of  the  tube.  The  metal  tube  is  placed 
in  the  animal 's  mouth  between  the  back  teeth ;  the  funnel  end 
is  held  at  a  convenient  height  and  medicine  poured  slowly  into 
it.  It  is  better  to  give  the  medicine  when  the  sheep  is  standing 
on  its  feet,  because  actual  experiment  has  demonstrated  that 
while  the  animal  is  in  this  position  more  of  the  medicine  goes 
directly  to  the  fourth  stomach,  where  it  is  needed.  The  head 
must  not  be  raised  too  high — not  higher  than  level  face ;  other- 
wise there  is  danger  of  passing  medicine  into  the  lungs. 

Prevention. — Sick  animals  must  be  killed,  or  removed  from 
the  flock  and  confined  where  there  is  no  drainage  tc  the  pas- 
ture or  yard  used  by  other  sheep  or  cattle.  Water  should  be 
taken  from  wells  that  do  not  receive  surface  drainage,  from 
large  lakes  or  from  running  streams,  although  stagnant  pools 
are  lorobably  not  so  dangerous  in  this  connection  as  is  commonly 
supposed.  The  tank  or  trough  should  be  high  enough  so  that 
the  water  cannot  possibly  be  contaminated  from  droppings. 
High  and  well-drained  pasture  is  always  safer  than  low  pas- 
tures so  far  as  internal  parasites  in  general  are  concerned.  In- 
fected pastures  should  be  burned  over  thoroughly  and  regu- 
larly for  the  purpose  of  destroying  eggs  and  young  worms. 

It  should  be  borne  in  mind  that  when  animals  are  well  fed 
and  well  nourished,  they  are  better  able  to  resist  the  invasion 
of  any  parasite. 


LECTURE  XXXI 

VERMINOUS  BRONCHITIS,  NASAL  GRUB,  AND 

CATARRH 

Verminous  Bronchitis 

Cause. — This  is  a  disease  of  the  bronchial  tubes  and  lungs, 
caused  by  several  species  of  minute  roundworms.  The  worms 
are  similar  in  different  domestic  animals,  but  each  animal  has 
its  own  species.  They  vary  from  about  one  to  three  inches  in 
length  and  are  white  or  reddish  to  brown  in  color.  There  is 
little  danger  of  infection  from  one  kind  of  domestic  animal  to 
another.  Sheep,  goats,  cattle,  and  pigs  are  subject  to  this 
disease.  Older  animals  may  be  aflfected,  but  frequently  carry 
the  parasite  without  evident  injury. 

Life  history. — The  mature  worms,  eggs,  and  embryos  are 
found  in  tlie  bronchial  tubes.  Either  eggs  or  embryos  are  de- 
posited in  the  bronchial  tubes.  Some  may  be  coughed  up,  then 
swallowed  and  pass  with  the  manure.  Future  hosts  take  in  the 
embryos  witli  food  or  drink,  usually  grass.  The  young  parasites 
then  go  to  the  lungs.  Apparently,  but  the  one  host  is  necessary. 
Wet  pastures  appear  to  be  favorable  to  the  spread  of  this 
trouble.  It  is  possible  that  the  eggs  or  dried  embryos  may  be 
inhaled  directly  with  particles  of  dust.  The  parasitism  remains 
long  dormant,  developing  slowly.  Embryos  are  very  resistant 
and  tenacious  of  life.  Some  species  have  been  shown  to  sur- 
vive for  months  as  embryos  in  water  or  moist  earth.  If  dried 
at  certain  stages  of  development,  the  embryos  may  revive  in 
moisture  after  a  year,  according  to  one  good  authority. 

Symptoms. — At  first  tlun-e  is  a  bronchial  catarrh ;  later  a 
clironic  anemia  and  pallor,  with  progressive  loss  of  flesh  and 
strength  and  with  sliortness  of  breath.  There  is  a  cough  which 
at  first  Is  rather  harsli,  and  later  very  weak.  The  cough  is 
worse  when  animals  are  excited  and  when  they  move  around. 
Sometimes  small  balls  composed  mainly  of  worms  may  be 
coughed  out  and  actually  seen.     Respiration  is  difficult  and  in 

153 


154  VETERINARY  STUDIES 

some  cases  accompanied  by  wheezing.  Calves  are  able  to  resist 
rather  longer  than  sheep. 

On  examination  post  mortem  there  may  be  found  masses  of 
minute  threadlike  worms  in  the  trachea  and  bronchial  tubes, 
with  a  considerable  quantity  of  purulent  and  viscid  liquid  in 
the  tubes.  Some  lobules  of  the  lungs  may  show  very  marked 
pneumonia.  There  may  also  be  tubercles  resembling  those  of 
tuberculosis,  near  the  surface  of  the  lungs,  and  also  throughout 
the  lung  substance. 

Treatment.— Treatment  by  injection  of  medicines  directly 
into  the  trachea  has  been  tried  and  recommended  in  some  cases, 
but  is  very  apt  to  prove  unsatisfactory. 

Benzine  has  been  tried  and  reported  successful.  Inject  about 
one  dram  (1  teaspoonful)  slowly  into  the  trachea.  Use  an 
ordinary  hypodermic  syringe  and  inject  directly  through  the 
side  of  the  trachea  between  two  rings.  The  sheep  must  be  held 
flat  on  the  side  at  the  time  of  injection  and  for  five  minutes 
afterward  with  the  head  as  low  as  possible.  It  would  be  wise 
to  treat  but  a  few  sheep  at  first  and  note  results. 

The  most  promising  treatment  at  present  is  by  chloroform. 
Inject  one-half  to  three-fourths  of  a  teaspoonful  of  chloroform 
into  the  nostrils  with  an  ordinary  medicine  dropper.  Hold  the 
head  up  and  close  the  nostrils  for  a  while.  It  would  be  well  to 
begin  this  treatment  cautiously. 

This  treatment  should  be  repeated  two  or  three  times  at  inter- 
vals of  three  to  five  days.  Calves  should  have  the  same  treat- 
ment with  proportionately  larger  doses. 

Prevention. — Change  pastures  often ;  keep  sheep  upon  forage 
crops  and  upon  frequently  changed  pastures.  Avoid  ponds,  and 
well  water  which  receives  drainage  from  pastures,  feed  lots  or 
barn  yards. 

Nasal  Grub — Sheep  (Grub  in  the  Head) 

This  is  a  very  poor  name  for  a  disease,  but  is  the  only  one 
commonly  understood,  and  is  used  here  for  that  reason. 

Cause. — This  disease  is  caused  by  the  larva?  of  a  fly  {Oestrus 
ovis).  This  larva  inhabits  the  various  cavities  of  the  head  which 
communicate  with  the  nasal  chambers.     See  figure  52. 

Life  history. — The  mature  fly  resembles  the  well  known  bot 
fly  of  the  horse,  is  of  a  dirty  yellow  or  grayish  yellow  color,  and 


VERMINOUS  BRONCHITIS,  NASAL  GRUB,  CATARRH  155 

appears  in  the  middle  of  the  day,  from  July  to  September. 
Sheep  become  excited  when  the  tiy  is  around,  and  hold  their 
noses  to  the  ground  or  against  each  other,  although  the  fly  does 
not  bite  or  sting.  The  young  larva^  are  deposited  about  the  nos- 
trils of  the  sheep  from  whence  they  crawl  up  into  the  various 
cavities  of  the  head,  including  the  horn  cores,  and  may  even 
reach  the  brain  substance.  They  mature  in  about  nine  or  ten 
months  and  escape  from  the  nose  during  the  spring  and  early 
summer.    They  then  pass  through  another  stage  before  the  adult 


Fig.  52. — Sheep  Gadfly   (CEstrus  ovis). 
Commonly  called  "nasal  grub."  a,  adult;   b,  larva;   c.  puparium. 


fly  appears,  which  occurs  in  four  to  seven  weeks  from  the  time 
the  grubs  escape  from  the  nose. 

Symptoms. — A  few  larvje  may  not  cause  any  evident  disturb- 
ance. When  present  in  larger  numbers,  the  parasites  cause 
great  irritation  accompanied  by  a  marked  catarrhal  discharge 
from  the  nostrils.  The  affected  animals  may  refuse  to  eat  well 
and  even  cough.  The  sheep  sneeze,  shake  their  heads,  and  rub 
their  noses  and  faces  against  their  feet  or  other  objects;  some- 
times there  are  attacks  of  vertigo,  and  the  walk  may  be  unsteady 
or  irregular ;  severe  eases  may  develop  con\'ulsions  and  die.  The 
nasal  mucous  membrane  becomes  thickened  and  this,  with  the 
discharge,  interferes  with  respiration.  Such  sheep  are  unthrifty 
on  account  of  the  constant  annoyance.  On  examination  post 
mortem,  grubs  are  found  in  the  various  openings  and  chambers 


156  VETERINAEY  STUDIES 

of  the  head,  and  the  mucous  membrane  lining  these  cavities  is 
inflamed. 

Treatment. — ]\Iedical  treatment  under  ordinary  circumstances 
is  not  practical;  but  much  of  the  trouble  may  be  prevented. 
Before  the  sheep  are  turned  out  in  the  morning,  their  noses 
may  be  smeared  with  tar  or  with  a  mixture  of  tar,  turpentine, 
and  fish  oil.  They  may  be  forced  to  take  their  salt  through  a 
large  hole  bored  in  a  log  or  a  plank,  tar  being  smeared  around 
the  edges  of  the  hole  so  that  when  the  sheep  take  their  salt,  they 
get  tar  around  the  nose  and  mouth. 

Catarrh  in  Sheep 

Sheep  catarrh. — A  form  of  catarrh  is  so  frequently  associated 
with  nasal  grub  that  it  seems  best  to  insert  a  brief  mention  of 
nonparasitic  catarrh  in  this  connection. 

Simple  catarrh  in  sheep  is  usually  due  to  bacteria,  after  cold 
rains,  imperfect  ventilation,  and  damp  quarters,  or  undue  ex- 
posure after  early  shearing  have  made  the  sheep  less  resistant. 
In  other  words,  it  is  a  case  of  so  called  ' '  catching  cold. ' '  Many 
other  cases  of  catarrh  are  due  to  parasitic  invasion  of  the  nasal 
chambers  and  head  sinuses. 

Symptoms. — The  affected  sheep  are  noticed  to  be  sneezing 
and  coughing  with  discharge  from  the  nose  and  eyes.  The  nasal 
discharge  is  thin  at  first,  gradually  becoming  thicker.  Some 
cases  become  chronic,  especially  when  the  subjects  are  weak 
and  unthrifty.  The  inflammation  of  the  nasal  mucous  mem- 
brane may  extend  into  the  head  sinuses,  causing  extensive  col- 
lections of  pus,  and  may  also  extend  down  the  mucous  mem- 
brane lining  the  trachea. 

Prevention. — Nonparasitic  catarrh  is  to  be  prevented,  first  of 
all,  by  abundant  ventilation.  Sheep  are  very  frequently  housed 
too  closely  in  winter ;  the  interior  of  the  building  becomes  damp, 
and  the  conditions  in  general  are  unwholesome.  Healthy  sheep 
do  not  need  much  protection  in  the  winter-time,  so  far  as  warmth 
is  concerned.  If  they  are  well  sheltered  from  cold  rains,  snows, 
and  cold  winds,  they  are  most  thrifty  with  abundant  ventilation. 
Sheep  that  are  shorn  early  in  the  spring  need  careful  manage- 
ment for  a  time  in  order  to  prevent  this  catarrh,  however. 

Treatment. — Sick  animals  must  have  shelter  which  is  dry, 
reasonably  warm,  and  well  ventilated.     They  must  be  well  fed. 


VERMINOUS  BRONCHITIS,  NASAL  GRUB,  CATARRH  157 

Their  medicinal  treatment  should  consist  mainly  of  tonics;  for 
instance,  a  simple,  bitter  vegetable  tonic,  like  gentian  root, 
which  may  be  given  in  a  powdered  form  in  the  feed  two  or  three 
times  daily— about  one  dram  per  sheep. 


INFECTIOUS  DISEASES 

LECTURE  XXXII 
ACTINOMYCOSIS— OR  LUMPY  JAW 

This  disease  is  commonly  called  lumpy  jaw  or  big  head.  It 
is  characterized  by  the  development  of  peculiar  enlargements 
containing  pus  pockets,  usually  around  the  head.  The  disease 
may  also  affect  other  external  parts  and  internal  organs. 

Cause. — The  tumors  and  abscesses  which  characterize  lumpy 
jaw  have  a  common  origin ;  namely  the  presence  and  activity 
of  a  form  of  higher  bacteria  known  as  actinomyces  {Actinomyces 
hovis)  aided  by  various  common  pus  producing  bacteria.  When 
the  abscesses  are  opened,  there  is  usually  found  in  the  interior, 
thick  glairy  pus  containing  minute  grains,  usually  yellow  and 
sometimes  very  abundant.  These  small  grains  may  be  bedded 
in  the  diseased  soft  tissues  of  the  tumors.  Seen  under  a  micro- 
scope, these  grains  appear  to  be  composed  of  radiating  fila- 
ments with  club-shaped  extremities  around  the  border  of  the 
mass.  In  artificial  media  it  forms  long,  slender  threads,  often 
branching.  As  the  fungus  multiplies  and  spreads  the  tumor 
growths  increase  in  size.  The  tumors  are  usually  very  firm  on 
account  of  the  large  amount  of  connective  tissue  which  they 
contain.  The  interior  is  somewhat  honeycombed,  and  the  pockets 
are  filled  with  characteristic  pus  containing  the  granules  of 
actinomyces.  Animals  affected  are  chiefly  cattle,  horses,  and 
sheep. 

Relation  to  public  health. — Human  beings  are  evidently  sus- 
ceptible to  inoculation  from  this  disease,  but  as  the  affected  parts 
of  diseased  carcasses  are  not  commonly  used  as  articles  of  human 
food,  and  animal  meats  as  a  rule  are  cooked  before  being  eaten, 
there  is  ordinarily  slight  danger  for  human  beings.  The  gov- 
ernment meat  inspection  regulations  pass  carcasses  which  are 
but  slightly  and  locally  diseased,  and  condemn  those  which  are 
extensively  and  generally  diseased. 

Parts  involved. — The  external  parts  commonly  affected  are 
the  bones  of  the  upper  and  lower  jaws,  soft  tissues  between  the 
two  branches  of  the  lower  jaw,  and  tongue.     This  disease  some- 

158 


ACTINOMYCOSIS— OR  LUMPY  JAW 


159 


times  affects  the  lungs  and  other  internal  organs,  and  may  be 
mistaken  for  tuberculosis.  The  lung  symptoms,  as  seen  on  ex- 
amination post  mortem,  vary  so  much  that  it  is  rather  difficult 
to  describe  them.  Sometimes  the  lungs  resemble  those  seen  in 
ordinary  bronchopneumonia.  Considerable  areas  of  the  lung 
tissue  may  be  changed  to  a  gray  mass,  soft  to  the  touch.  In 
still  other  cases  there  are  developed  distinct  abscesses  with  fluid 
contents. 


Pig.  .53. — Actinomycosis — Lumpy  Jaw.     (M.  II.  K.) 
Note  the  enlarged  jaw  and  the  raw,  granulating  tissue  exposed. 


This  disease  is  usually  of  slow  development.  A  small  swell- 
ing appears  somewhere  about  the  head,  perhaps  under  the 
tongue;  or  the  bones  of  the  face  near  the  teeth  begin  to  bulge 
slightly  outward  and  the  enlargements  continue  very  slowly. 
The  animal  may  remain  thrifty  for  a  long  time,  or  indeed  until 
the  disease  involves  the  teeth,  tongue,  or  other  organs  and  inter- 
feres directly  with  nutrition. 

Prevention. — There  is  so  little  known  concerning  the  life  his- 
tory of  the  parasite  and  the  methods  of  infection  that  a  study 
of  prevention  can  be  only  partially  satisfactory.  It  is  generally 
agreed  that  animals  develop  lumpy  jaw  only  after  inoculation, 


160 


VETERINARY  STUDIES 


i.e.,  when  the  germs  find  entrance  throngh  some  cut  or  scratch 
in  the  skin ;  throngh  the  mucous  membrane  of  the  mouth  on 
account  of   diseased   teeth;   or  through   some  abrasion   of   the 


Fig.  54. — Actinomycosis.     (M.  H.  B.) 
Inferior  maxilla  of  cow  shown  in  Fig.  53. 

mucous  membrane  of  the  mouth,  gullet,  or  stomach.  It  is  also 
generally  agreed  that  the  parasite  is  usually  taken  in  with  the 
food.  It  is  possible  that  this  fungus  may  live  through  one  stage 
of  its  development,  and  even  multiply,  upon  the  surface  or  in 


Fig.  55. — Actinomycosis.     (M.  U.  E.) 
A  badly  diseased  upper  jaw. 

the  tissues  of  some  of  the  common  fodder  plants,  particularly 
barley  and  rye.  Direct  inoculation  from  one  animal  to  another 
usually  fails  to  reproduce  the  disease. 


ACTINOMYCOSIS— OR  LUMPY  JAW  161 

An  animal  with  a  discharging  abscess  about  the  head  would 
of  course  infect  food  in  mangers,  feeding  troughs,  and  grass  in 
the  pasture,  thus  ottering  abundant  opportunities  for  infection. 
Pastures  wherein  cases  of  lumpy  jaw  seem  to  develop  rather 
commonly  should  be  placed  under  cultivation  for  a  time  and 
animals  with  discharging  abscesses  confined  or  sent  to  market, 
it  being  conceded  by  all  authorities  that  most  of  these  carcasses 
killed  under  inspection  are  fit  for  food  uses  and  should  not  be 
wasted  by  condemnation. 

Treatment. — There  are  several  possible  lines  of  treatment : 
surgical,   caustic,  and  internal  medication. 

Surgical  treatment. — Removal  by  knife  should  be  undertaken 
only  by  a  trained  veterinarian,  on  account  of  the  large  blood 
vessels  and  other  important  structures  involved. 

Caustic. — Destruction  of  the  tumor  mass  by  caustics,  arsenic 
paste,  for  example  is  satisfactory  in  suitable  cases,  where  there 
is  time  for  a  slow  cure  and  the  case  is  not  far  advanced.  This 
work  should  also  be  done  by  a  trained  veterinarian.  Deep 
hypodermic  injections  of  tincture  of  iodin  or  of  Lugol's  iodin 
give  good  results  in  some  cases.  This  iodin  treatment  causes 
large  swelling  and  violent  inflammation,  which  seems  to  react 
unfavorably  upon  the  actinomyces. 

Internal  medication. — This  treatment  consists  of  tlie  internal 
use  of  iodid  of  potash,  given  by  tlie  mouth  either  as  a  drench  or 
in  the  drinking  water.  Lugol's  iodin,  by  deep  hypodermic  in- 
jection into  the  tumor,  may  be  combined  with  the  internal  treat- 
ment. Early  eases  may  be  treated  in  this  way  with  a  good 
prospect  of  success. 

The  dose  limit  is  about  one  fourth  dram  per  one  hundred 
pounds  live  weight.  This  dose  is  given  once  daily  until  the 
animal  seems  to  get  off  feed  and  discharges  freely  from  the 
eyes  and  nose,  indicating  a  catarrhal  disturbance  of  these  mu- 
cous membranes.  The  skin  will  also  become  drv,  wrinkled  and 
scurfy.  Such  conditions  indicate  that  the  treatment  should  be 
discontinued  for  three  or  four  days.  During  tliis  period  a  mild 
cathartic  of  epsom  salts  about  one  pound  to  1000  pounds  live 
weight,  should  be  dissolved  in  water  and  given  as  a  drench.  The 
iodid  treatment  may  then  be  continued  for  another  period  of 
six  to  ten  days,  when  it  may  be  necessary  to  discontinue  again 
and  give  another  dose  of  ei)som  salts.  Treatment  sliould  be 
continued  until  the  tumor  is  reduced  to  about  one  third  of  its 


162  VETERINARY  STUDIES 

original  size.     It  may  as  well  be  discontinued  if  there  are  no 
favorable  results  in  4  or  5  weeks. 

The  time  required  for  successful  treatment  in  suitable  cases 
varies  from  four  to  seven  weeks.  It  is  not  advisable  to  under- 
tjake  the  treatment  of  any  case  where  there  is  evident  bony 
enlargement,  or  where  there  is  serious  disease  of  the  bony  struc- 
ture, lodid  treatment  is  liable  to  check  milk  flow  and  spoil  the 
flavor  of  the  milk. 


LECTURE  XXXIII 
ANTHRAX ' 

One  of  the  oldest  diseases  known  to  medical  science  and  one 
which  is  almost  world  wide  is  anthrax.  It  afifects  a  wide  range 
of  subjects  and  is  usually  fatal. 

Animals  affected. — All  of  the  domestic  farm  animals  are  more 
or  less  susceptible  to  anthrax.  The  disease  is  transmissible,  and 
very  fatal  to  human  beings,  chiefly  by  inoculation,  but  it  may 
be  taken  by  means  of  food  or  water,  or  by  the  inhalation  of 
dried  spores. 

Cause. — Anthrax  is  caused  by  a  microscopic  rod-shaped  or- 
ganism or  germ,  the  Bacterium  anthracis.  The  rod  stage  of 
the  organism  is  found  in  living  blood,  ^^^ 

immediately    after    death,    while    the 


spore  stage  occurs  outside  of  the  body.       •«««^^— — — •« 
The  rod  is  more  easily  destroyed  than     fig.     56.— b  a  c  t  e  r  i  u  m 
is  the  spore.    The  spore  may  retain  its        (Bacillus)^Anthracis. 

vitality    in    surface    soil,    manure,    in-         The  specific 'cause  of  an- 
fected  foodstuffs,  blood,  hides,  hair  and     thrax. 
w'ool  of  anthrax  victims  for  long  pe- 
riods, and  be  capable  of  causing  fresh  outbreaks.     A  contamin- 
ated pasture  for  example  remains  infectious  for  years. 
•    The  period  of  incubation  is  probably  short.    In  experimental 
animals  it  varies  from  one  to  five  days. 

No  true  toxin  has  been  demonstrated  for  this  virus;  but  B. 
anthracis  may  be  present  in  the  blood  in  such  numbers  as  to 
block  the  capillaries.  It  also  produces  an  enzyme  which  digests 
blood  serum  and  destroys  the  red  corpuscles. 

Modes  of  infection.— (1)  Dried  spores  may  be  inhaled  and  so 
reach  the  general  circulation  by  way  of  the  capillaries  of  the 
lungs.  Human  beings  following  certain  occupations,  as  wool 
sorting,  mattress  making,  etc.,  obtain  infection  in  this  way  more 
often  than  do  the  lower  animals. 

'  This  lecture  contributed  originally  by  Dr.  W.  H.  Dalrymple,  of  Louisiana, 
and  later  revised  by  the  author. 

163 


164  VETERINARY  STUDIES 

(2)  When  infection  is  introduced  by  inoculation  through 
the  skin,  there  results  the  condition  known  as  external  anthrax, 
carbuncular  disease,  inoculation  anthrax,  or  malignant  pustule. 
This  may  be  occasioned  by  insects,  especially  of  the  blood-suck- 
ing varieties,  such  as  the  various  horse  or  gad  flies;  probably, 
also,  by  some  varieties  of  the  mosquito.  The  infection  may 
come  through  wounds  made  by  infected  instruments  or  uten- 
sils; or  by  wounds  coming  in  contact  with  virulent  material. 
In  the  Lower  IMississippi  Valley  the  external  form  occurs  very 
frequently,  and  some  outbreaks  extend  over  considerable  terri- 
tory, among  horses  and  mules,  on  account  of  the  vast  numbers 
of  horseflies  during  the  summer  months. 

(3)  Infection  may  occur  through  the  digestive  tract.  This 
internal,  or  intestinal,  form  of  anthrax  is  generally  produced 
by  taking  the  virus  in  contaminated  food  or  water. 

Methods  of  introduction  and  spread. — Anthrax  virus  may  be 
introduced  by  imported  hides,  hair,  wool,  etc.,  from  foreign 
countries  infected  with  anthrax.  Fertilizing  materials  manu- 
factured from  animals  affected  with  the  disease  may  be  a  source 
of  infection,  also  running  water  may  become  contaminated  and 
spread  infection  along  its  course.  The  refuse  water  from  tan- 
neries has  been  known  to  disseminate  infection  from  anthrax 
hides.  Insects,  after  feeding  upon  infected  blood  and  tissues, 
may  carry  the  virus  to  healthy  animals  at  a  distance.  Insects 
may  probably,  also,  infect  food  materials  in  troughs  and  man- 
gers, by  conveying  virulent  matter  on  their  bodies  and  feet. 
Carrion  birds,  through  the  medium  of  their  excrement  or  soiled 
feet,  may  infect  pastures  on  which  they  alight.  Carnivorous 
and  omnivorous  animals,  as  dogs  and  hogs,  running  at  large, 
after  feeding  upon  anthrax  carcasses,  may  carry  away  viru- 
lent blood  on  their  feet;  and  if  these  animals  themselves  die, 
they  become  fresh  centers  of  the  disease. 

Foodstuffs,  as  grass,  cereal  grains  and  their  by-products,  hay, 
etc.,  raised  upon  lands  infected  with  anthrax  spores,  may  carry 
those  spores  and  spread  the  disease.  Human  beings  coming  in 
contact  with  virulent  anthrax  material,  and  having  their  clothes, 
shoes,  hands,  etc.,  soiled  thereby,  may  spread  the  disease  to 
animals.  Neglect  to  properly  dispose  of  anthrax  carcasses  is, 
perhaps,  the  factor  most  responsible  for  the  continuance  and 
spread  of  anthrax. 

Period  of  incubation.— The  time  that  elapses  between  infee- 


ANTHRAX  165 

tion  and  symptoms  depends  upon  the  method  of  infection  and 
the  amount  of  infective  material  introduced,  and  may  range 
from  a  very  few  hours  to  several  days. 

Symptoms. — In  cj-ffnial  or  cuitincous  anthrax,  there  is  swell- 
ing at  the  point  or  points  of  inoculation  (carbuncle  or  ma- 
lignant pustule),  with  considerable  local  edema  (localized  watery 
swelling).  This  is  painful  and  hot  at  first,  but  afterwards  be- 
comes cold  and  insensitive.  If  inoculations  have  been  made  by 
insects,  the  carbuncles  may  be  numerous  over  different  parts  of 
the  body.  Tlie  swellings  extend  in  the  connective  tissue  along 
the  course  of  the  lymjili  vessels  and  glands.  This  form  is  seen 
most  frequently  in  tlie  thinner-skinned  herbivora — horse,  mule, 
etc. 

In  internal  anthrax,  we  have  various  types  of  the  disease,  espe- 
cially a  pulmonary  or  thoracic  and  an  abdominal  form.  Symp- 
toms vary  accordingl.y  and  diagnosis  even  by  an  experienced 
veterinarian  is  not  always  easy.  Some  cases,  especially  the  first 
ones,  die  very  suddenly.  The  illness  may  last  from  a  very  few 
hours  to  several  days.  In  general  there  are :  sudden  seizure, 
great  depression,  and  ])rostration ;  rapid  rise  to  high  tempera- 
ture ;  stupor ;  muscular  weakness  and  twitchings ;  vertigo ;  hur- 
ried respirations ;  increased  heart  action ;  visible  mucous  mem- 
branes are  hemorrhagic,  dark  red  or  a  bluish  red  color  or  ooz- 
ing l)lood ;  sometimes  the  coloring  matter  of  the  blood  appears 
in  the  urine.     Such  cases  usually  terminate  fatally. 

External  manifestations  in  the  hog  are  usually  confined  to  the 
throat ;  and  there  are  generally  other  symptoms  of  a  specific 
fever  present.  As  a  rule,  death  takes  place  from  asphyxia. 
The  hog  becomes  infected  from  eating  anthrax  carcasses ;  and 
the  disease  is  most   frequent  in  this  animal  during  epizootics. 

Course  of  the  disease. — In  isolated  cases,  in  limited  outbreaks, 
and  in  tlie  early  stage  of  an  outbreak,  the  course  of  the  disease 
is  usually  very  acute  and  rapid;  Avhih",  toward  the  termination 
of  tlie  outbreak,  anthrax  seems  much  less  fatal,  many  of  the 
affected  animals  recovering.  Or,  in  other  words,  the  virulence 
of  the  disease  seems  to  become  weakened  toward  the  end  of  the 
outbreak,  or  the  most  susceptible  animals  die  first  and  with 
acute  cases. 

Examination  post  mortem. — On  are-uunt  of  the  danger  to  the 
operator,  and  the  risk  of  spreading  the  disease,  through  the 
infectivity  of  the  blood,  post-mortem  examination  of  an  anthrax 


166  VETERINARY  STUDIES 

carcass  is  dangerous.  It  is  therefore  recommended  only  under 
very  unusual  conditions,  when  undertaken  by  an  expert  fa- 
miliar with  the  danger  incurred,  and  where  possible  spread  of 
the  virus  can  be  controlled. 

Diagnosis. — In  carcasses  of  animals  dead  from  anthrax,  there 
is  very  rapid  decomposition  and  bloating.  The  blood  is  dark 
and  does  not  clot.  Exposure  of  the  blood  to  air  does  not  restore 
its  normal  red  color.  The  spleen  is  greatly  enlarged.  There 
may  be  bloody  discharge  from  rectum,  bladder,  nostrils,  etc. 
Severe  inflammation  of  various  internal  organs,  with  local 
hemorrhages,  is  common  in  acute  cases.  Local  swellings  under 
the  skin  are  not  tilled  with  gas,  and  do  not  crackle  under  pres- 
sure, as  do  those  of  blackleg. 

Diagnosis  is  safest  and  most  reliable  by  microscopic  examina- 
tion of  a  small  quantity  of  blood  from  the  extremities  (ear  of 
larger  animals,  or  a  foot  of  the  smaller),  verified  by  inoculation 
of  laboratory  animals  with  anthrax  blood,  and  followed  by 
microscopic  examination  of  the  blood  of  the  inoculated  animals. 

Treatment. — Ordinary  medical  treatment  appears  useless  in 
most  cases. 

Prevention. — Prevention  by  vaccination  should  be  practiced 
annually  in  anthrax  districts,  or  in  sporadic  outbreaks,  as  re- 
quired, and  is  very  important.  There  is  a  small  risk  of  loss 
from  vaccination  anthrax ;  but  the  loss  is  less  serious  than  risk 
from  the  disease. 

There  should  be  cremation  of  carcasses ;  very  thorough  dis- 
infection of  premises  (stables,  sheds,  yards,  etc.)  ;  drainage  and 
cultivation  of  infected  lands ;  destruction  of  horseflies,  mosqui- 
toes, etc. ;  drainage  of  pools  and  stagnant  water  where  these 
insects  breed  or  frequent ;  and  effective  live-stock  sanitary  leg- 
islation. 

There  are  now  three  methods  of  vaccinating;  (a)  by  single, 
reduced  virus  vaccine;  (&)  by  serum  with  virus;  (c)  by  double 
virus  (reduced). 

The  serum-virus  method  should  be  used  for  horses  and  sheep, 
and  for  cattle,  when  the  disease  has  already  appeared  in  the 
herd.  The  single  virus  is  not  usually  advisable.  The  double 
virus  vaccine  should  be  used  for  cattle  when  there  is  serious  risk 
of  infection,  but  the  actual  disease  has  not  yet  appeared. 

Serum  only  should  be  given  in  affected  herds,  to  animals  of 
any  kind  showing  fever  and  not  in  hopeless  condition. 


LECTURE  XXXIV 
SYMPTOMATIC  ANTHRAX 

Symptomatic  aiitlirax  is  also  known  as  blacklcp',  bl-ick  quarter, 
eU'.  It  is  a  fatal,  infections  ami  enzootie  disease  of  thrifty 
yonngr  eattle.  It  is  ai)t  to  appear  year  after  year  on  certain 
pastures  oi-  along  certain  valleys.  Cattle  more  than  two  years 
of  age  are  not  usually  affeetecl.  Sheep  and  goats  are  subject  to 
this  disease,  but  cases  are  rare.  Attack  and  recovery  gives 
immunity. 

Cause. — A  short  spore-forming  bacillus  {Bacillus  chauvoei) 
causes  this  disease.  This  bacillus  produces  spores  and  the  spores 
are  very  resistant,  being  able  to  renuiin  virulent  in  the  soil  for 
years — under  favorable  conditions.  Infection  usually  occurs  by 
inoculation,  through  the  skin  or  mucous  membrane;  more  com- 
monly through  the  former.  So  far  as  it  is  known,  this  disease 
is  not  contagions  by  mere  association.  The  period  of  incubation 
is  short — about  3  to  5  days.  Authorities  are  not  fully  agreed 
but  B.  chauvoei  is  apparently  a  producer  of  a  virulent  toxin. 

Symptoms. — The  symptoms  are  local,  and  general  or  consti- 
tutional. 

Local  symptoms. — There  is  usually  a  pronounced  swelling  in- 
volving the  front  or  liind  quarter,  and  occasionally  the  loin, 
breast  or  throat.  It  does  not  extend  below  the  hock  or  knee. 
This  swelling  is  characterized  by  crepitation  as  one  passes  the 
hand  over  it,  due  to  an  accumulation  of  gas  in  the  loose  sub- 
cutaneous tissues.  An  incision  inio  the  swelling  reveals  llie 
presence  of  dark,  frothy  blood,  with  ixM-uliar  acetone  odor. 
The  swelling  is  not  invariable.  Some  cases,  especially  those 
which  appear  at  the  beginning  of  the  outbreak  and  die  very 
suddenly,  may  not  show  the  characteristic  swelling. 

Constitutional  symptoms. — The  constitutional  symptoms  ai-e 
usually  acute,  and  develop  rapidly.  The  animal  is  dull  and 
without  appetite.  It  shows  high  fever  and  marked  debility. 
The  constitutional  symptoms  may  last  from  one  to  three  days, 
and  the  case  usually  terminates  fatally.     The  fever  may  reach 

167 


168  VETERINARY  STUDIES 

106°  or  even  107°  F.  There  is  lameness  in  those  cases  which 
show  local  swellings  of  the  front  or  hind  qnarters.  Some  cases 
are  mild  and  misleading  and  diagnosis  is  not  always  easy.  The 
dnration  of  typical  cases  is  from  a  few  hours  to  several  days. 

Examination  post  mortem. — Examination  of  the  carcass  re- 
veals a  tnmor  tilled  with  gas  and  dark,  frothy  blood  with  fetid 
odor.  The  spleen  is  normal,  and  blood  from  the  general  cir- 
culation is  also  apparently  normal,  clotting  readily  on  expo- 
sure to  air.  In  such  features  as  normal  spleen,  normally  clotting 
blood,  and  gas-tilled  tumor,  the  disease  differs  from  true  anthrax. 

Carcasses  decompose  and  bloat  rapidly  and  dark  frothy  blood 
may  ooze  from  the  natural  openings  as  in  true  anthrax.  The 
muscles  involved  in  the  local  lesions  are  very  dark  when  first 
exposed  to  the  air,  and  hemorrhagic  conditions  are  common  in 
the  chest  and  abdominal  cavities. 

Prevention. — As  soon  as  the  disease  appears,  cattle  under  two 
years  of  age  should  be  promptly  changed  to  another  and  pref- 
erably higher  pasture.  If  the  young  cattle  have  been  on  dry 
food,  their  food  then  should  be  changed.  Such  feed  may  be 
safely  given  to  horses  however.  Blackleg  carcasses  should  be 
handled  like  those  of  anthrax,  to  avoid  scattering  the  virus  of 
a  serious  disease. 

Vaccination  is  now  satisfactory  and  thoroughly  practical. 
There  are  a  number  of  commercial  preparations  on  the  market 
that  are  quite  reliable.  The  federal  Bureau  of  Animal  Industry 
is  supplying  a  blackleg  vaccine,  which  is  quite  satisfactory. 
Method  of  vaccination  depends  upon  the  kind  of  preparation 
used.  Directions  usually  accompany  each  shipment  from  any 
of  the  reliable  makers. 

Vaccination 

The  vaccine. — The  Bureau  or  government  vaccine  consists  of 
a  brownish  powder  furnished  in  packets  of  ten  and  twenty-five 
doses  each.  It  is  made  from  the  muscle  of  animals  affected  with 
blackleg,  and  is  prepared  by  drying  the  muscle  and  grinding 
and  heating  it  to  a  temperature  which  lowers  the  virulence  of 
the  bacilli,  but  does  not  destroy  them. 

Preparation. — The  needed  outfit  consists  of  a  graduated  hypo- 
dermic syringe  of  about  5  c.c.  capacity:  rather  short,  stout 
needles  of  good  caliber,  and  sharp ;  a  small  mortar  and  pestle ; 


SYMPTOMATIC  ANTHRAX  169 

absorbent  cotton  for  filtering,  and  a  measure  graduated  for 
cubic  centimeters. 

All  these  must  be  sterilized  by  boiling,  or  otherwise,  before 
using.  The  vaccine  is  i)repared  for  use  by  emptying  a  given 
number  of  doses  into  thv  mortar,  adding  a  few  drops  of  boiled 
and  cooled  water,  and  thoroughly  grinding.  Then  as  many 
cubic  centimeters  of  water,  boiled  and  cooled,  are  added  as 
there  were  doses  of  vaccine.  This  is  well  mixed,  filtered  in 
the  funnel  through  loosely  packed  cotton,  and  the  filtered  liquid 
is  used  for  the  vaccination.  The  injection  is  made  by  hypo- 
dermic syringe  on  the  side  of  the  neck  or  back  of  the  shoulder. 

Dose. — The  dose  is  1  c.c.  for  yearlings  and  somewhat  less  for 
younger  animals,  down  to  .5  c.c.  for  calves. 

Suggestions. — It  is  not  usually  necessary  to  vaccinate  calves 
under  six  months  nor  over  two  years.  If  calves  under  six 
months  are  vaccinated,  they  may  require  revaccination  next 
season.  Vaccination  should  be  given  a  few  weeks  before  this 
trouble  usualh'  appears,  as  the  disease  tends  to  appear  at  ap- 
proximately the  .s.ame  time  each  year.  Vaccination  should  not  be 
given  to  calves  that  are  weak  from  disease  or  ill  health,  nor  at 
the  same  time  with,  or  soon  after,  any  surgical  operation  like 
castration.  There  should  be  an  interval  of  at  least  ten  days 
after  the  latter  operation.  Calves  that  are  accustomed  to  being 
handled  may  be  vaccinated  standing  in  the  stable.  Those  that 
are  wild  must  usually  be  thrown  or  confined  in  a  chute. 

There  are  several  newer  immunizing  preparations  now  on  the 
market:  (1)  Aggression,  prepared  by  extracting  juices  from  dis- 
eased tissue  under  pressure,  filtering  and  preserving  by  phenol 
(carbolic  acid)  ;  (2)  filtrate,  a  filtrate  from  a  laboratory  artifi- 
cial culture  of  B.  chauvai,  and  preserved  by  phenol;  (3)  anti- 
hlackleg  serum,  from  the  blood  of  horses  that  have  had  a  series 
of  weekly  injections  of  blackleg  virus  in  large  doses.  This 
serum  seems  to  have  some  curative  value  early  in  the  case. 

Treatment. — ^ledical  treatment  for  this  disease  is  not  con- 
sidered satisfactory  or.  as  a  rule,  worth  while.  Prevention  by 
vaccination  is  easily  applied,  inexpensive,  and  usually  satis- 
factory. 


LECTURE  XXXV 

BACILLUS  NECROPHORUS  INFECTIONS 

Here  we  have  a  group  of  similar  diseases,  each  due  princi- 
pally to  B.  necrophorus.  Included  in  this  group  are:  foot-rot 
of  sheep,  foul  foot  in  cattle,  lip  and  leg  ulceration  of  sheep, 
canker  sore  mouth  in  young  pigs,  and  necrotic  enteritis  of  older 
hogs.  In  each  case,  the  characteristic  lesion  is  a  local  inflam- 
mation with  a  marked  tendency  to  local  necrosis,  for  example, 
an  ulcer  or  a  diphtheritic  membrane. 


Fig.  57. — Bacillus  Necrophorus.     (B.  A.  I.) 
Coccoid,  bacillary  and  filamentous  forms. 

Cause. — The  principal  cause  of  necrophorus  infections  is 
Bacillus  necrophorus.  A  distinctive  peculiarity  of  this  bacillus 
is  its  tendency  to  destroy  local  tissue  through  its  products. 

This  bacillus  is  associated  with  filth.  It  is  apparently  a  nor- 
mal inhabitant  of  the  intestines  of  swine,  and  perhaps  of  other 
animals.  Infection  is  therefore  liable  to  come  from  manure  or 
from  contaminated  soil,  soil  recently  fertilized  with  hog  ma- 
nure, for  example. 

170 


BACILLUS  NECROPHORUS  INFECTIONS         171 

Infection  occurs  in  all  these  diseases  by  inoculation,  throngli 
wounds  of  skin  or  mucous  membranes,  as  when  little  pigs  are 
teething-.  The  lesions  produced  de])end  on  the  point  of  inocula- 
tion, age  and  species  of  the  animal,  the  virulence  of  the  infec- 
tion and  the  character  of  the  associated  bacteria. 

Losses  are  often  serious,  especially  in  lip  and  leg  ulceration, 
canker  sore  mouth,  and  foot-rot. 

In  dealing  ^vith  any  of  these  diseases,  it  is  of  the  utmost 
importance  that  one  be  on  guard  for  the  first  case.  Prompt 
treatment  with   early  isolation  checks  or  lessens  their  spread. 


Foot-Rot 

Foot-rot  is  a  very  old  and  familiar  disease.  It  is  often  insidi- 
ous at  first,  the  appetite  appearing  good,  and  the  lameness 
slight ;  but  it  must  be  taken  seriously  at  the  beginning,  and 
treated  promptly,  lest  it  extend  to  the  deeper  structures  and 
involve  even  the  bone.     Most  outbreaks  are  infectious. 

Cause. — A  large  percent- 
age of  these  cases  are  caused 
by  Bacillus  necropJiorus;, 
which  is  commonly  found 
in  dirt  and  barn  yard  filth. 

General  symptoms. — This 
disease  usually  affects  the 
feet  and  produces  lameness, 
slight  and  perhaps  in  one 
fore  foot  only  at  first,  be- 
tween and  above  the  claws. 
Later  the  lameness  becomes 
severe.  There  is  a  dis- 
charge, with  very  offensive  odor,  and  the  hoof  itself  becomes 
rotten  in  places.  Loose  pieces  are  detached  and  the  sole  may  be 
affected  in  the  same  way.  The  sensitive  parts  may  l)e  exposed 
in  very  severe  eases  with  a  development  of  profuse  granulations. 
The  skin  above  and  between  the  hoofs  is  red,  tender  and  swollen, 
and  the  toes  are  widely  spread.  The  animal  is  lame  and,  of 
course,  unthrifty. 

The  discharge  is  at  first  fluid  and  fetid.  After  one  or  two 
weeks  it  becomes  cheesy  and  foul,  and  seems  to  destroy  the  horn 
and  skin  which  it  touciies.     In  from  twenty  to  thirty  days  the 


Fig.  58. — Foot-Rot  op  Sheep. 
A  plain  case. 


172  VETERINARY  STUDIES 

claw  begins  to  separate ;  there  appears  to  be  great  pain ;  tlie 
sheep  travels  on  its  knees.  Several  months  after  the  beginning 
of  the  disease,  the  claws  may  drop  off  in  improperly  treated  or 
neglected  cases. 

Differential  diagnosis. — It  is  necessary  to  distinguish  between 
foot-rot  and  a  very  different  disease  which  we  know  as  "foot- 
and-mouth  disease."  Foot-rot  begins  in  the  skin  between  the 
claws  or  at  the  crown  of  the  foot,  and  slowly  involves  the  wall 
and  sole.  It  then  spreads  both  as  to  surface  and  depth,  involv- 
ing the  deeper  structures  of  the  foot.  Foot-and-mouth  disease 
may  also  begin  with  an  inflammation  of  the  skin  between  the 
claws  or  just  above  the  hoofs.  The  skin  becomes  red,  then  small 
vesicles  or  blisters  develop  which  rupture  and  later  dry.  In 
foot-and-mouth  disease  the  whole  hoof  may  loosen  early  at  the 
crown,  the  inflammation  involving  especially  the  skin  at  the 
crown  and  sensitive  parts  under  the  wall  and  above  the  sole. 
In  foot-rot  the  horn  is  diseased  and  separates  in  pieces.  Foot- 
and-mouth  disease  affects  several  feet  and  perhaps  the  mouth 
and  udder,  also, — simultaneously.  Foot  rot  usually  affects  one 
foot  at  first,  and  there  is  little  or  no  fever  in  common  cases, 
whereas  in  foot-and-mouth  disease  the  fever  is  characteristic. 

Foot-rot  develops  slowly,  the  animals  usually  eating  fairly 
well  for  some  time.  This  is  not  the  case  with  foot-and-mouth 
disease,  Avhich  spreads  readily  from  sheep  to  cattle  and  swine. 
Foot-rot  does  not  spread  from  one  species  to  another. 

Treatment. — Clean  thoroughly  between  the  toes;  pare  away 
all  diseased  horn  and  remove  the  loosened  pieces.  The  hoof, 
if  grown  out  of  shape,  must  be  trimmed  to  normal  proportion. 
Excessive  granulations  must  be  cut  away  or  removed  by  actual 
cautery,  and  be  repressed  by  astringent  measures  or  pressure 
bandages.  Pledgets  of  tow  may  be  dipped  in  tar  and  applied 
over  the  granulations,  so  as  to  bring  pressure  at  the  right  point. 
Patients  so  treated  should  be  kept  upon  clean  dry  footing,  and 
serious  eases  should  be  taken  up  and  kept  in  the  yard  or  in  dry 
stc.bles.  For  astringent  dressing,  use  tincture  of  iron,  varying 
it  from  full  strength  to  1  to  4  dissolved  in  water.  Four  per 
cent  carbolized  tar  makes  a  good  application  for  cleansing  and 
disinfecting  and  keeps  out  dirt.  Medical  treatment  particularly 
the  astringent  should  be  very  carefully  applied,  especially  in 
the  crevices  and  deeper  recesses. 

It  is  frequently  advisable  to  treat  a  whole  flock  in  a  general 


BACILLUS  NECROPHORUS  LNFLCTIONS         173 

way.  In  that  case  the  flock  may  be  driven  through  a  large  pan 
containing  a  solution  which  is  about  four  inches  deep  and  the 
animals  should  be  forced  to  remain  in  the  pan  for  several 
minutes  to  insure  thorough  treatment.  This  solution  should  be 
made  by  dissolving  copper  sulphate  in  water  in  the  proportion 
of  one  pound  to  a  gallon  of  water,  or  use  chlorid  of  lime  solu- 
tion made  by  dissolving  one  pound  of  fresh  chlorid  of  lime  to 
three  gallons  of  water. 

Separate  the  diseased  from  the  apparently  healthy.  Treat 
the  latter  firs^t  and  move  these  to  a  clean  place,  e.g.,  new  pas- 
ture. If  any  of  these  become  lame,  examine,  and  if  found 
diseased,  move  them  to  the  diseased  flock.  Repeat  trough  treat- 
ment several  times  for  the  sound  flock  at  about  two-day  inter- 
vals. The  diseased  flock  should  have  the  same  general  treat- 
ment, repeated  and  continued  as  long  as  necessary.  Trough 
treatment  is  satisfactory  for  both  sound  and  average  cases-, 
severe  cases  must  have  individual  hand  treatment. 

Prevention  and  management. — Diseased  animals  should  be 
isolated  from  the  healthy  ones.  Vigorous  and  repeated  clean- 
ing and  disinfections  of  the  infected  premises  are  necessary  to 
the  proper  control  and  must  begin  early.  Any  good  coal  tar 
dip  in  5  per  cent  strength  will  do.  Either  very  wet  or  very 
dry  pastures  may  be  favorable  to  the  development  of  the  disease. 
Hoofs  should  be  kept  pared  to  reasonable  proportions.  Cases 
of  foot-rot  should  not  be  neglected  in  the  earlier  stages,  for  they 
are  much  easier  treated  then.  They  may  be  infectious,  and 
careful  treatment  and  attention  may  prevent  a  general  outbreak. 

Foul-Foot 

This  is  a  disease  of  cattle  resembling  foot-rot  of  sheep  and  is 
apparently  infectious,  and  due  in  most  cases  to  Bacillus  necro- 
phonis,  which  causes  foot-rot. 

Treatment. — Trim  off  diseased  horn  freely.  It  is  sometimes 
advisable  in  the  early  inflammatory  stages  to  poultice  with  bran 
or  oilmeal,  using  powdered  charcoal  (|uite  freely  in  the  poul- 
tice.   For  mild  cases,  white  lotion  may  be  used  once  daily. 

For  more  serious  cases,  use  ten  per  cent  solution  of  any  good 
coal  tar  dip  in  glycerine  once  a  day  for  two  or  three  days,  then 
reduce  to  a  5  per  cent  solution  and  use  every  other  day  for  a 
week  or  two  as  necessary. 


174  VETERINARY  STUDIES 

After  trimming  and  cleaning,  some  cases  are  well  treated,  by 
swabbing  freely  with  lysol,  or  full  strength  sheep  dip,  or  some 
other  disinfectants,  and  then  drying  and  applying  a  powder 
like  scarlatone,  or  compound  alum  powder  or  calomel. 

It  is  sometimes  advisable  to  use  a  roll  of  tar-soaked  oakum, 
pressed  well  up  between  the  toes,  and  held  in  place  by  a  tar 
bandage  around  the  foot.  Where  new  tissue  seems  to  grow 
too  rapidly,  it  may  be  repressed  by  means  of  small  pads  of 
oakum  or  tow,  soaked  with  tar  and  bandaged  firmly  over  the 
part  that  needs  checking. 

For  astringent  effect  upon  the  granulations,  tincture  chlorid 
of  iron,  full  strength  or  diluted  as  indicated  to  one  fourth  with 
water,  may  be  used.  Four  per  cent  carbolic  acid  in  tar  is  very 
useful,  especially  as  it  tends  to  keep  out  dirt  and  foreign  matter. 

Lip-and-Leg  Ulceration 

In  this  disease  of  sheep  we  again  have  local  necrosis  as  the 
chief  characteristic.  This  disorder  may  occur  in  conneccion  with 
foot-rot. 

Symptoms. — The  chief  symptom  of  this  trouble  is  the  ulcers 
upon  the  skin  most  commonly  of  the  legs,  or  upon  the  mouth 
parts,  especially  lips  and  muzzle.  The  ulcers  have  dry  crusts 
with  a  granulating  surface  beneath.  They  may  invade  the 
mucous  membrane  of  the  mouth  or  nostril,  or  even  of  the  eye. 
There  is  often  a  considerable  slough  and  an  offensive  odor. 
Some  cases  are  slight  and  chronic ;  others,  more  severe. 

Treatment. — Scrape  off  the  dead  and  the  spongy  tissue,  then 
apply  to  the  diseased  area  either  zinc  chlorid  or  silver  nitrate, 
10  per  cent  in  water,  and  repeat  three  times  a  Aveek,  or  second, 
use  an  ointment  of  vaseline  or  lard,  one  hundred ;  sulphur,  10 ; 
any  good  dip,  five.  Under  good  treatment  prognosis  is 
favorable. 

Canker  Sore  Mouth  (Stomatitis) 

Canker  sore  mouth  is  also  due  to  B.  necraphorus,  affects 
young  pigs  as  a  rule  and  older  shoats  occasionally.  It  is  a 
troublesome,  difficult  disease  to  manage  after  there  has  been  a 
general  spread  of  the  virus.  Ground  surfaces,  floors,  bellies  of 
brood  sows,  etc.,  soon  become  contaminated  with  the  infection. 
Many  cases  occur  during  the  teething  of  young  pigs. 


BACILLUS  NECROPHORUS  INFECTIONS         175 

Calves  have  a  similar  trouble  (calf  diphtheria)  due  to  the 
same  virus  and  characterized  by  patches  of  diphtheritic  mem- 
brane in  the  mouth,  nose,  larynx,  and  even  the  trachea.  The 
necrotic  areas  in  calves  are  much  larger  than  in  pigs. 

Symptoms. — Canker  sore  mouth  is  easily  recognized  by  the 
small   ulcers  Avhich  arc  most  common  in  the  mouth  or  on  the 


Fig.  59. — Lip-and-Leg  Ulceration.     {B.  A.  I.) 
Produced  by  artificial  infection  with  Bacillus  necrophorus. 

skin  near  the  mouth.  They  may  invade  the  nose  and  adjacent 
cavities,  and  the  trachea,  and  even  extend  to  the  intestines. 

Prevention  and  management. — Keep  brood  sows  and  pigs 
away  from  the  foot-rot  of  cattle  and  sheep  and  from  what  may 
be  necrotic  enteritis  in  other  hogs.  Avoid  old  pens  and  yards. 
In  case  of  outbreak,  only  the  most  thorough  cleaning  and  re- 
peated disinfection  will  suffice. 

When  the  season  permits,  it  may  be  necessary  to  move  sows 
and  litters  repeatedly  to  fresh  grounds,  and  in  some  cases,  it 
may  pay  to  clean  and  disinfect  the  sow's  belly  before  the  pigs 
are  allowed  to  nurse. 


176  VETERINARY  STUDIES 

Treatment. — Both  the  affected  and  the  suspected  pigs  should 
be  dipped  to  the  ears  two  or  three  times  a  day  for  several  days 
in  some  good  coal  tar  dip  of  5  per  cent  strength. 

In  case  of  valuable  pigs  the  individual  ulcers  may  be  cleaned 
and  treated  with  20  per  cent  silver  nitrate,  applied  by  a  very 
small  cotton  swab. 

Necrotic  Enteritis 

Necrotic  enteritis  is  an  infectious  inflammation  of  the  bowels 
of  older  hogs,  due  to  B.  necrophorus.  It  is  sometimes  mistaken 
for  hog  cholera  and  is  often  a  complication  of  that  disease. 

Symptoms. — Diagnosis  in  the  living  animals  is  difficult  and 
uncertain.  It  may  involve  any  portion  of  the  mucous  membrane 
of  the  digestive  tube. 

Autopsy  shows  the  typical  local  necrosis  involving  this  mem- 
brane,— typical  ulcers  and  larger  patches  of  diphtheritic  mem- 
brane covered  with  yellowish,  cheesy  material. 

There  may  be  hemorrhages  on  the  mucous  membrane  of  the 
intestine,  kidneys  and  other  organs,  resembling  the  hemorrhages 
of  hog  cholera.  However  necrotic  enteritis  is  usually  a  slow 
disease  and  high  fever  is  not  characteristic  as  in  hog  cholera. 

Treatment. — Present  methods  of  treating  necrotic  enteritis 
are  very  unsatisfactory.  There  is  as  yet  nothing  to  be  positively 
recommended.  ]\Iany  cases  are  undoubtedly  complications  of 
hog  cholera.     In  ease  of  doubt,  use  hog  cholera  serum. 

Prevention  and  management. — Infection  occurs  by  inocula- 
tion; therefore,  avoid  feed  and  feeding  conditions  favorable  to 
this  virus  and  liable  to  produce  the  abrasion  necessary  to  infec- 
tions.    The  smallest  scratch  is  sufficient  for  inoculation. 

Various  intestinal  parasites  may  undoubtedly  injure  the  in- 
testinal mucosa,  and  permit  infections.  Treatment  for  the 
worms  is  therefore  required  as  a  preventive  of  this  form  of 
enteritis. 


LECTURE  XXXVI 
FOOT-AND-MOUTH  DISEASE 

Foot-and-mouth  disease  is  a  very  contagious  disease,  chiefly 
of  ruminant  animals  and  swine,  but  horses  and  other  animals 
are  susceptible  to  it.  Some  outbreaks  are  much  more  virulent 
than  others.  ^Nlany  cases  are  so  mild  as  to  be  difficult  to  recog- 
nize; but  whether  they  are  virulent  or  mild  they  are  always 
a  serious  matter  for  the  owner  of  the  stock,  even  though  no 
animals  die,  and  a  very  serious  matter  for  the  public  because 
of  extreme  ease  and  rapidity  of  spread,  the  great  difficulty  and 
expense  of  eradication  and  actual  money  losses  incurred.  Sev- 
eral outbreaks  have  occurred  in  this  country  due  to  importa- 
tions, but  they  were  eradicated  and  so  far  as  known  we  have 
none  in  America  at  the  present  time. 

Cause. — The  cause  is  a  filterable  and  apparently  invisible 
virus.  Little  is  known  about  it  except  as  to  its  disease  produc- 
ing power. 

Infection. — Usually  takes  place  by  way  of  the  digestive  tube. 

Symptoms. — The  symptoms  are  here  given  for  cattle.  Sheep 
and  swine  show,  in  general,  similar  symptoms. 

Foot-and-mouth  disease  develops  in  from  three  to  five  days 
after  exposure.  Affected  cattle  are  first  noticed  to  be  sluggish. 
They  shiver  and  later  on  are  stiff  and  lame,  and  inclined  to  lie 
down  by  reason  of  the  sore  feet.  There  is  a  profuse  flow  of 
the  saliva,  with  frequent  swallowing  motions  and  smacking  of 
,the  lips.  The  peculiar  lesions  of  the  foot-and-mouth  disease 
are  vesicles  or  small  blisters  affecting  the  mouth  and  the  skin 
above  and  between  the  hoofs,  and  over  tiie  udder  and  teats. 
The  vesicles  soon  break,  leaving  raw  surfaces  which,  as  a  rule, 
heal,  but  sometimes  remain  as  rather  chronic  ulcers.  The  skin 
and  superficial  tissues  around  the  hoofs  become  inflamed  and 
swollen ;  the  stomach  may  also  be  involved ;  weight  is  lost,  and 
the  milk  flow  is  checked.  Tt  should  be  remembered  that  the 
symptoms  vary   greatly   in   virulence   in   different   animals  and 

177 


178  VETERINARY  STUDIES 

different  outbreaks,  and  one  patient  does  not  usually  show  all 
these  symptoms. 

This  disease  is  not  ordinarily  fatal,  but  it  causes  very  serious 
losses  in  the  checked  milk  flow,  a  prolonged  unthrifty  condi- 
tion, and  seriously  diseased  feet.  There  is  a  marked  fever, 
highest  just  before  the  eruption  appears.  Active  symptoms 
of  the  disease  last  from  eight  to  fourteen  days.  Disease  of 
the  skin  around  the  hoofs  often  follows  the  mouth  symptoms 
but  the  two  may  occur  together.  When  the  disease  affects  sheep 
and  swine  it  is  apt  to  involve  especially  the  feet.  Many  cases 
are  obscure  and  difficult  of  recognition.  Others  are  severe 
and  easily  recognized.  Some  show  no  mouth  symptoms  and 
others  no  foot  symptoms. 

There  are  several  diseases  that  are  easily  mistaken  for  foot- 
and-mouth  disease.     (See  Foot-rot.) 

Vesicular  sio'rnatitis  affects  horses  and  cattle.  The  mouth 
symptoms  are  similar,  but  there  are  no  foot  or  udder  lesions 
and  horses  are  not  apt  to  have  foot-and-mouth  disease.  Hogs 
and  sheep  have  foot-and-mouth  disease,  but  not  vesicular 
stomatitis. 

Cow  pox  and  sheep  pox  are  of  slow  development  and  slow 
spread  and  show  pustules  after  the  vesicles.  They  rarely  affect 
any  parts  except  the  udder  and  adjacent  skin. 

Dissemination. — The  infecting  virus  may  be  present  in  yards, 
stables,  and  on  the  food  or  feeding  utensils  on  infected  farms. 
Even  a  road  over  which  diseased  animals  have  passed  may  be 
infectious.  This  disease  may  be  disseminated  in  an  indefinite 
number  of  ways,  and  is  recognized  as  one  of  the  most  easily 
scattered  of  the  infectious  diseases.  The  infectious  material 
is  apparently  present  in  the  discharge  from  the  vesicles,  in  the 
saliva,  milk,  urine,  manure,  and  perspiration.  The  infection 
is  probably  obtained  through  the  respiratory  or  digestive 
organs,  usually  the  latter. 

Prevention. — The  prevention  of  this  disease  is  simply  the 
prevention  of  infection.  Infected  premises  that  have  not  been 
disinfected  may  remain  infectious  for  an  undetermined  period. 
Until  we  have  more  positive  information  on  this  point,  we  may 
say  that  it  will  hardly  be  safe  to  risk  exposure  in  less  than  a 
year  unless  the  premises  can  be  thoroughly  disinfected. 

This  disease  spreads  rapidly;  it  causes  heavy  losses,  and  is 
difficult  to  control  after  it  has  become  widely  scattered.     Any 


FOOT-AND-MOUTH  DISEASE  179 

reasonable  suspicion  of  its  existence  should  be  promptly  re- 
ported to  the  local  health  ofifieer  and  every  possible  precaution 
taken  to  prevent  spread. 

Treatment  is  not  advised.  It  is  usually  advisable  to  kill  and 
burn  every  diseased  and  exposed  animal  on  the  farm.  The 
owner  is  then  reimbursed  by  the  state  and  government. 


LECTURE  XXXVII 
HEMORRHAGIC  SEPTICEMIA 

This  group  of  diseases  is  important  because  of  its  many  forms, 
and  because  medical  treatment,  so  far  as  we  know,  is  useless, 
and  prevention  is  very  uncertain.  Those  who  have  had  a 
chance  to  study  outbreaks  have  often  been  unable  to  trace  any 
connection  between  one  outbreak  and  another,  or  to  trace  a 
previous  history  for  any  given  outbreak,  except  that  local  out- 
breaks on  farms  often  follow  the  advent  of  stock  from  public 
stockyards.  This  disease  is  worthy  of  serious  consideration,  be- 
cause it  is  widespread  and  fatal.  It  appears  suddenly  at  any 
season,  and  under  all  sorts  of  conditions ;  a  number  of  animals 
die,  and  the  disease  may  disappear  as  suddenly  as  it  came. 

Etiology. — The  specific  cause  of  this  disease  in  cattle  is  appar- 
ently Bacillus  hovisepticus.  This  is  one  of  a  group  of  very  sim- 
ilar bacteria,  which  cause  a  group  of  similar  diseases  in  different 
classes  of  stock,  e.g.,  chicken  cholera,  hemorrhagic  septicemia  of 
cattle  and  of  sheep,  swine  plague,  septic  pneumonia  of  calves, 
etc.  All  are  characterized  by  hemorrhages  in  the  tissues  or 
under  the  skin,  mucous  membranes  or  serous  membranes.  In- 
fection may  be  caused  by  inoculation  or  through  the  respira- 
tory or  alimentary  mucous  membranes. 

History  and  development. — The  onset  is  usually  sudden  and 
unexpected,  but  in  some  outbreaks  the  onset  is  rather  slow, 
and  the  cases  are  chronic.  The  period  of  incubation  is  prob- 
ably only  a  matter  of  a  few  days.  Season  and  climatic  condi- 
tions apparently  have  nothing  to  do  with  the  prevalence,  viru- 
lence or  disappearance  of  this  disease.  The  death  rate  is  usually 
high. 

Symptoms. — Symptoms  in  the  living  animal  are  variable  and 
uncertain.  There  are  several  fairly  distinct  types  of  the  dis- 
ease in  sheep  and  cattle,  and  symptoms  vary  accordingly :  Some 
cases  are  marked  by  superficial  swelling,  severe  inflammation, 
and  small  hemorrhages  of  the  mucous  membranes  of  the  eye, 

180 


HEMORRHAGIC  SEPTICEMIA 


181 


nose,  or  month.  Other  cases  show  symptoms  of  pneumonia  with 
pleurisy — difficult,  hurried,  and  joainful  res])iration  and  fever. 
Calves  frecjuently  have  this  type  of  the  disease.  Some  cases 
show  abdominal  pain,  high  fever,  and  abnormal  movements ; 
and  their  attitudes  indicate  abdominal  discomfort.  In  the 
writer's  experience,  the  temperatures  have  been  either  normal 
or  subnormal  except  where  they  rose  rapidly  just  before  death 
occurred. 

Local  changes  which  correspond  to  the  swellings  of  anthrax 


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Fig.  60. — HEiMOrrhagic  Septicemia.     {M.  E.  E.) 
Meningeal  type.     Cow  stupid.     Early  stage. 


and  sj^mptomatic  anthrax  are  occasionally  present;  usually, 
however,  tliev  ai'e  either  limited  or  else  wanting. 

The  urine  in  some  cases  is  scanty  or  l)h)od-stained,  and  this  is 
also  true  of  the  l)owel  discharges. 

Many  cases  of  hemorrhagic  septicemia,  particularly  those  oc- 
curring in  cattle,  are  of  the  meningeal,  or  nervous  type.  In  this 
type  of  the  disease,  some  cases  early  sliow  an  extreme  nervous 
disturbance,  while  others  develop  such  symptoms  gradually. 
Cows  whii'h  iiave  given  a  normal  flow  of  milk  in  the  morning 
may  give  practically  none  in  the  evening ;  they  are  otherwise 
apparently  normal.     There  may  be  no  rise  of  temperature;  and 


182 


VETERINARY  STUDIES 


no  evidence  of  pain  or  discomfort.  Later  when  they  attempt 
to  walk,  the  gait  is  more  or  less  irregular,  resembling  very  much 
the  gait  of  milk  fever  in  its  early  stage.  The  symptoms^  dur- 
ing the  first  2-1  to  36  hours  are  not  marked,  except  that  dull- 
ness, staggering  gait,  and  cold  extremities  continue.  The  skin 
is  harsh  and  lacking  in  sensation. 

Still  later  diarrhea  often  appears  and  nervous  symptoms  be- 
come  more   pronounced.     The   inability    to   walk   naturally   is 


Fig.  61. — Hemorrhagic  Septicemia.     (M.  E.  B.) 
Hemorrhages   on   costal    pleura. 


continued ;  the  neck  may  be  bent  to  one  side,  and  the  muscles, 
particularly  of  the  face  and  neck,  are  spasmodically  contracted. 
The  sick  animals  may  remain  quiet,  moving  around  very  little; 
but  the  eyes  have  a  wild  expression,  and  there  may  be  a  nervous 
chewing  motion  with  profuse  flow  of  saliva.  The  temperatures 
are  often  normal  or  even  subnormal. 

Later  still  there  often  appears  intense  nervous  activity.  The 
eyes  become  more  wild  and  unnatural ;  the  grinding  of  the  jaAvs 
grows  more  active  and  more  constant;  the  convulsions  of  face 

*  In  case  of  young  calves,  these  cases  may  be  characterized  by  profound 
nervous  disturbance  very  early  in  their  histories. 


HEMORRHAGIC  SEPTICEMIA 


183 


and  neck  muscles  become  more  intense ;  then  gradually  a  period 
of  intense  restlessness  and  activity,  and  death. 

Examination  post  mortem. 
— The  blood  is  apparently 
normal. 

Subcntaneous  h emorrhages 
are  common  and  vary  greatly 
in  size  and  intensity.  In 
some  cases  they  are  large  and 
the  hemorrhagic  condition  is 
marked;  in  others  they  are 
minute,  scattered,  and  few  in 
number.  They  may  appear 
almost  anywhere  in  the  sub- 
cutaneous tissues,  or  involve 
any  of  the  internal  organs; 
and  they  usually  have 
sharply  defined  borders  and 
are  easily  recognized  as  hem- 
orrhages. 

The  spleen  is  not  enlarged, 
but  there  may  be  hemor- 
rhages on  its  surface. 

The  serous  and  mucous  membranes  frequently  show  small 
hemorrhagic  areas,  and  the  heart,  especially  its  auricles,  is 
often  intensely  hemorrhagic. 


Fig.    62.- 


-Hemorrhagic   Septicemia. 
(M.  H.  R.) 


Hemorrhages    on    endocardium    (in- 
ternal lining  of  tlie  lieart). 


Differential  Diagnosis 

It  is  very  imi)ortant  to  distinguish  between  blackleg  and 
hemorrhagic  septicemia,  because  we  have  no  demonstrated  vac- 
cine or  serum  either  preventive  or  curative  and  no  medical 
treatment  for  hemorrhagic  septicemia,  whereas  blackleg  can  be 
easily  and  cheaply  i)revented  by  vaccination. 

In  both  diseases,  death  is  lial)le  to  occur  suddenly,  but  black- 
leg commonly  affects  only  cattle  under  two  years  of  age,  and 
rarely  young  calves;  wliereas  hemorrhagic  septicemia  affects  all 
ages  indiscriminately.  High  temperatures  are  characteristic  of 
blackleg,  but  not  of  hemorrhagic  septicemia.  Pronounced  swell- 
ing of  the  front  or  hind  ([uarter  is  characteristic  of  blackleg, 
although  in  some  cases  which  die  very  suddenly  there  may  be  no 


184 


VETERINARY  STUDIES 


noticeable  swelling.  Swellings  of  this  kind  are  not  characteristic 
of  hemorrhagic  septicemia,  and  when  present  are  small.  Blood 
taken  from  a  blackleg  swelling  is  dark  and  frothy,  and  has  a 
peculiar  odor.     This  does  not  apply  to  hemorrhagic  septicemia. 


Fig.  63. — Hemorrhagic  Septicemia.     {M.  H.  R.) 
Hemorrhages  (dark  spots)  on  peritoneal  surface  of  intestine. 


Blackleg  carcasses  bloat  rapidly;  the  others  do  not.  The  stu- 
dents should  compare  hemorrhagic  symptoms  with  anthrax  also, 
and  note  the  characteristic  ditferences. 


LECTURE  XXXVIII 
TEXAS  OR  TICK  FEVERS 

This  disease  passes  under  a  variety  of  names,  such  as  acclima- 
tion fever,  red  water,  liloody  murrain,  etc. 

Economic  importance. — The  seriousness  of  tick  fever  as  a 
disease  of  cattle,  and  its  bearing  upon  the  southern  cattle  indus- 
try, was  not  realized  until  recent  years. 

Causes. — It  has  been  established  that  the  disease  is  caused  by 
a  microscopic  animal  parasite,  a  protozoan  {Piroplasma  higemi- 
num)  which  attacks  the  red  cor- 
puscles of  the  blood.  Its  multi- 
plication in  the  blood  is  rapid 
and  its  effects  are  destructive,  in- 
volving especially  the  red  blood 
corpuscles,  which  it  destroys 
rajiidly. 

Transmission.  —  So  far  as 
known,  the  only  natural  means 
of  transmitting  the  causative 
agent  of  this  disease  is  the  south- 
ern cattle  tick  {Margaropus  an- 
nulatus)..  Other  species  of  ticks 
attack  southern  cattle,  but  this  is 
the  most  common  and  is  the  only 
one  responsible  for  transmission 
of  the  Texas  Fever  parasite. 

The  ticks  do  not  carry  the  pro- 
tozoan directly  from  one  in- 
fected animal  to  another,  but  the  female  ticks  develop  on  in- 
fected animals  and  tlien  transmit  the  Piroi)lasma  in  some  form 
to  their  progeny,  which  carry  it  to  susceptible  animals. 

Susceptibility. — Bovines  alone  seem  susceptible  to  the  dis- 
ease, although  the  tick,  which  carries  the  infection,  occasionally 
infests  horses  and  mules.    Calves  at  birth  as  a  rule  have  a  high 

^This  lecture  contributed  by  Dr.  Tait  Butler. 

185 


Fig.  64. 


Female  engorged. 
annulatus  (Riley). 


Tkxas  Fever  Tick. 
{Pettit.) 

Margaropus 


186  VETERINARY  STUDIES 

degree  of  immunity;  but  this  immunity  is  gradually  lost  until 
at  two  years  of  age  nearly  all  are  highly  susceptible  to  the 
disease.  Cattle  reared  in  the  southern  states  on  tiek-free  pas- 
tures are  as  susceptible  as  those  raised  in  the  North. 

Period  of  incubation. — Tick  fever  usually  develops  in  from 
eight  to  ten  days  after  direct  inoculation  of  a  susceptible  ani- 
mal with  the  blood  of  one  infected,  or  that  has  acquired  im- 
munity from  a  previous  attack.  When  infection  occurs  in  the 
natural  way,  a  variable  time  elapses  between  exposure  to  tick 
infestation  and  the  development  of  the  disease.  In  some  cases 
no  evidences  of  the  disease  can  be  detected  before  from  fifteen 
to  thirty— or  even  ninety — days  after  exposure.  However,  a 
large  percentage  of  cases  develop  within  ten  days  after  inocu- 
lation. 

Symptoms. — It  is  frequently  stated  that  tick  fever  occurs  in 
acute  and  chronic  forms.  The  chronic  form,  however,  often 
follows  the  acute,  and  appears  months  after  the  acute  attack. 
These  relapses  or  secondary  attacks  are  not  uncommon  in  the 
late  fall  and  early  winter.  It  is  then  difficult  to  distinguish 
them  from  ordinary  debility  from  other  causes  except  by  the 
history  of  a  previous  attack  or  by  an  examination  of  the  blood. 

Fever. — In  the  acute  type  of  the  disease  an  elevation  of  tem- 
perature is  usually  the  first  noticeable  s^-mptom.  A  tempera- 
ture of  107  degrees  or  108  degrees  F.  is  not  unusual,  but 
when  it  reaches  105  degrees  or  106  degrees,  other  symptoms 
usually  become  apparent.  While  there  are  considerable  fluc- 
tuations, temperature  generally  remains  high  during  five  to  seven 
days  and  may  then  drop  suddenly  to  normal  or  below.  Many 
animals  die  during  the  extremely  high  temperature,  or,  if  the 
temperature  falls,  it  is  only  as  a  prelude  to  death.  The  period 
of  subnormal  temperature  is  a  dangerous  one,  and  collapse 
should  be  fortified  against ;  otherwise  an  animal  may  succumb 
that  might  by  proper  treatment  have  been  saved. 

Other  symptoms. — The  patient  usually  stands  apart  from  the 
herd  with  head  down  and  back  arched,  and  in  severe  cases,  or 
when  death  approaches,  it  may  lie  or  fall  down.  The  pulse 
and  respiration  are  hurried.  The  urine  may  be  highly  colored 
as  port  wine,  or  almost  black,  especially  in  fatal  cases  and  when 
near  death.  The  red  is  coloring  matter  from  the  red  corpuscles, 
w^hich  are  rapidly  destroyed  by  the  blood  parasites  (P.  higemi- 
num).     Other  diseases  producing  bloody  urine  are  rare  among 


TEXAS  OR  TICK  FEVER  187 

cattle  in  this  country.  At  first  the  bowels  are  constipated,  hut 
later  diarrhea  is  not  uncommon.  The  mucous  membranes  are 
usually  pale  and  sometimes  slijjrhtly  yellow.  As  death  approaches 
and  the  symptoms  become  aggravated,  the  animal  iLSually  re- 
mains down.  Occasional  periods  of  excitement,  or  even  convul- 
sions, may  oceur. 

The  ticks  are  usually  to  be  found  on  the  tender  parts  of 
the  skin,  such  as  between  the  hind  legs,  on  the  escutcheon,  on 
the  inside  of  the  elbows,  or  on  the  brisket,  which  is  most  exposed. 
Since  the  disease  may  develop  within  ten  days  after  ticks  attack 
the  animal,  and  this  time  is  not  sufficient  for  them  to  become 
larger  than  twice  the  size  of  a  pinhead,  it  will  be  readily  ap- 
preciated that  to  find  the  ticks  is  not  always  an  easy  matter, 
especially  if  they  are  not  numerous. 

Post-mortem  appearances. — Only  in  animals  that  die  during 
an  acute  attack  are  the  changes  well  marked,  and  of  those  just 
the  more  pronounced  will  be  given.  Other  changes  may  be  seen, 
but  they  are  often  slight,  or  else  absent.  Small  ticks  on  the 
parts  mentioned  are  very  significant.  The  hlood  is  very  thin 
and  watery. 

The  subcutaneous  tissue  may  be  slightly  yellow  and  infiltrated 
with  yellow-colored  serum. 

In  cases  that  succumb  during  the  height  of  or  just  after  the 
subsidence  of  the  fever,  the  spleen  is  much  enlarged  and  dark 
colored.  When  held  up  by  one  end,  the  contents  of  the  cap- 
sule will  tend  to  gravitate  to  the  lower  end.  When  cut  it  is 
found  to  be  black,  soft,  and  engorged  with  blood. 

The  liver  is  enlarged,  yellowish,  and  usually  mottled  in  color, 
due  to  bile-injection.  The  gall  bladder  is  distended  wath  bile, 
which  is  dark  colored,  thick  and  ropy. 

The  kidneya  are  usually  engorged  and  dark,  and  the  bladder 
contains  urine  varying  in  color  from  slightly  red  to  almost 
black. 

Treatment. — Treatment  usually  proves  unsatisfactory,  and  the 
results  scarcely  justify  the  expense  and  trouble  which  it  entails, 
except  in  very  valuable  animals,  and  in  mild  cases.  The  whole 
herd  should  be  moved  to  non-infested  ground  and  the  ticks  re- 
moved at  least  from  the  sick  animals.  During  the  first  stages, 
when  constipation  is  present,  a  purgative  of  about  one  pound 
of  Epsom  salts  may  be  given.  The  salts  sliould  be  followed  by 
quinin  30  to  90  grains  or  an  equivalent  four  times  a  day.     If 


188  VETERINARY  STUDIES 

the  temperature  drops  to  normal,  or  below,  stimulants  should 
be  used  freely  for  a  short  time  and  be  followed  by  iron  and 
stryehnin  until  convalescence  is  established. 

When  the  first  ease  appears  in  a  herd,  all  other  animals 
that  have  been  similarly  exposed  to  tick  infestation  should  be 
removed  from  further  danger  of  such  exposure,  and  thoroughly 
greased.  Any  cheap,  nonirritating  oil  will  do,  but  if  it  be  one 
fourth  kerosene,  it  will  be  more  effective.  AVhen  a  dipping  vat 
is  available,  dipping  in  the  arsenical  solution,  now  used  in  tick 
eradication,  is  preferable  to  local  treatment  by  oil.  In  this  way 
an  outbreak  can  usually  be  cut  short,  and  the  losses  reduced 
very  considerably. 

Prevention. — Immunity  to  tick  fever  in  mature  animals,  so 
far  as  we  now  know,  can  only  be  secured'  through  an  attack  of 
the  disease.  Cattle  raised  on  tick-infested  pastures  have  been 
rendered  immune  by  mild  attacks  of  the  disease  while  they  were 
young  and  before  they  became  fully  susceptible.  If  it  is  true 
that  immunity  can  only  be  secured  through  an  attack  of  the 
disease,  it  follows  that  the  only  preventive  is  the  exclusion 
or  eradication  of  the  tick. 

The  ticks  on  any  pasture  or  farm  may  be  easily  and  quickly 
eradicated,  and  the  farm  maintained  free  from  them.  Hence, 
it  is  possible,  if  not  yet  practicable,  to  exterminate  these  para- 
sites over  the  entire  South  and  maintain  the  country  tick-free. 

Methods  by  AVhich  Ticks  May  be  Eradicated 

1.  Keep  all  cattle,  mules,  and  horses  out  of  the  tick-infested 
pasture,  lanes,  and  lots  for  one  season,  or,  at  least,  after  Sep- 
ber  1,  and  the  ticks  will  be  exterminated  by  May  of  the  next 
spring.    Or, 

2.  Divide  the  pasture  by  a  fenee^  with*  a  rail  or  board  tight 
on  the  ground  or  make  a  double  fence — two  fences  10  to  20  feet 
apart, — and  keep  all  cattle,  mules,  and  horses  out  of  one  half, 
this  year  after  September  1 ;  and  out  of  the  other  half  next  year, 
and  the  work  of  eradicating  the  ticks  will  have  been  accom- 
plished.    Or, 

3.  Dip  all  cattle  in  the  standard  arsenical  solution  once  every 
14  days  from  early  spring  until  late  fail.  If  this  is  done  regu- 
larly and  thoroughly  the  ticks  will  certainly  be  eradicated 
in  one  season. 


TEXAS  OR  TICK  FEVER  189 

Life  history. — The  methods  just  given  are  based  on  the  fol- 
lowing facts  concerning  the  life  histoiy  of  this  tick:  the  full- 
grown  female  tick  drops  off  the  cattle  when  she  becomes  en- 
gorged with  blood.  Her  heavy  body  and  small,  short  legs  make 
crawling  difficult,  so  she  gets  under  the  dry  grass,  or  ''trash" 
close  at  hand.  Within  a  few  days  she  begins  laying  eggs,  and 
lays  from  1,500  to  2,500  during  the  next  two  weeks.  In  Avarm 
weather,  under  favorable  conditions,  these  eggs  hatch  in  two 
or  three  weeks.  The  period  may  be  prolonged  for  eight  weeks, 
or  indeed,  the  hatching  be  prevented  entirely,  if  the  weather  is 
sufficiently  cold. 

The  young  ticks  are  very  small  when  first  hatched,  being 
scarcely  visible.  They  crawl  up  the  grass,  weeds,  or  small  twigs, 
and  there  wait  for  the  cattle  to  come  along.  If  no  cow,  mule, 
or  horse  comes  along  for  several  months,  these  small  ticks  die 
from  starvation,  for  they  have  no  other  known  means  of  obtain- 
ing food  for  development.  If  the  young  ticks  succeed  in  lodg- 
ing upon  the  skin  of  a  cow,  then  in  three  or  four  weeks  (and  in 
cold  weather  much  longer)  they  reach  their  full  growth.  The 
females,  being  engorged  with  blood,  drop  off  and  begin  laying 
eggs  as  did  their  mothers. 

Neither  old  nor  young  ticks  crawl  far,  hence  a  fence  with  a 
bottom  rail  or  board  on  the  ground  will  stop  them,  but  wire 
fences  do  not  always  afford  protection. 

Ticks  do  not  crawl  from  one  animal  to  another. 

Eggs  laid  during  the  cold  weather  of  late  fall  and  early 
winter  do  not  hatcli,  but  go  through  the  winter  as  eggs  and  hatch 
Avhen  warm  weather  comes  in  the  spring. 

All  eggs  laid  before  September  1  will  probably  hatch  the 
same  fall,  and,  therefore,  the  young  ticks  will  be  killed  by  the 
cold  winter  weather  or  starve  to  death  before  spring. 

Vaccination. — Not  only  does  tick  fever  kill  hundreds  of  thou- 
sands of  dollars'  worth  of  Southern  cattle  every  year  and  depre- 
ciate the  value  of  all  those  marketed  from  one  fourth  to  one  half 
cent  per  pound  live  weight,  but  it  also  offers  the  greatest  exist- 
ing barrier  to  the  improvement  of  the  quality  of  cattle  in  the 
tick-infested  area  by  rendering  the  imi)ortation  of  ])ure-bred 
animals  for  breeding  purposes  extra  hazardous  and  expensive. 

For  the  purpose  of  conferring  immunity  on  imported  pure- 
bred or  other  cattle,  a  method  of  inoculation  has  been  found 
practicable  which  very  greatly  reduces  the  otherwise  heavy  loss. 


190  VETERINARY  STUDIES 

Method.^ — The  usual  process  consists  in  drawing  blood  from 
the  jugular  vein  of  an  animal  (not  less  than  two  years  old)  that 
was  infested  with  ticks  the  preceding  summer,  and  injecting  it 
under  the  skin  of  the  animal  to  be  inoculated.  This  will  pro- 
duce tick  fever,  usually  in  a  mild  form  in  from  three  to  ten 
days.  Not  more  than  about  three  per  cent  will  die  from  this 
inoculation  if  the  subjects  have  been  selected  with  proper  care 
and  are  judiciously  handled.  About  5  to  7  per  cent  are  im- 
perfectly immunized. 

Tlie  dose  varies  from  1  to  3  c.c,  depending  on  the  age  of  the 
animal.  Young  cattle  take  the  larger  dose  and  older  cattle 
the  smaller.  Cattle  that  do  not  show  plain  reaction,  fever,  de- 
pression, etc.,  should  receive  a  second  or  even  a  third  treat- 
ment, each  dose  being  50  per  cent  larger  than  the  preceding 
and  given  at  intervals  of  about  40  days.  Young  cattle  less  than 
one  year  old  may  be  immunized  by  the  use  of  young  seed  ticks 
but  this  method  is  not  recommended  where  the  blood-inoculaticn 
method  is  available  and  is  not  at  all  suitable  for  older  cattle. 

Important  conditions. — The  animals  should  be  between  six  and 
fifteen  months  old.  Older  cattle  may  be  treated,  but  they  are 
less  conveniently  handled  and  results  are  less  satisfactory. 

The  inoculating  should  preferably  be  done  during  December, 
January,  or  February,  for  tick  fever  is  less  severe  in  cold 
weather. 

All  ticks  should  be  kept  off  the  inoculated  cattle  for  about 
60  days  or  until  they  have  fully  recovered  from  the  inoculation 
fever. 

The  inoculated  cattle  may  then  be  protected  for  a  time  from 
gross  tick  infestation  by  having  their  legs  and  under  parts  of 
their  bodies  greased.  A  few  ticks  after  the  cattle  have  fully 
recovered  from  inoculation  are  useful  as  they  reinforce  the 
immunity. 

Inoculated  animals  on  infected  premises  should  be  infested 
with  the  first  crop  of  ticks  appearing  in  the  spring,  for  these 
are  probably  less  virulent  than  those  hatched  in  the  fall,  and 
therefore  produce  a  milder  type  of  disease. 

In  the  opinion  of  the  writer  the  best  method  of  introducing 
jiure-bred  animals  for  improvement  of  the  native  stock  is  to 

'  See  also  Federal  Bureau  of  Animal  Industry  and  State  Ag^rieultural 
Experiment  Station  bulletins  on  Texas  Fever  for  additional  details  of 
vaccination. 


TEXAS  OR  TICK  FEVER  191 

import  calves  that  are  under  four  months  of  age  and  allow  them 
to  become  immunized  by  tick  infestation,  as  occurs  with  our 
native-born  stock.  But  since  the  eradication  of  the  ticks  is  now 
such  an  easy  matter,  the  only  practical  method  of  dealing  with 
tick  fever  is  to  prevent  it  by  complete  eradication  of  the  ticks. 


LECTURE  XXXIX 
TUBERCULOSIS 

The  importance  of  the  tuberculosis  question  is  evidenced  by 
its  widespread  prevalance,  human  susceptibility  to  bovine  in- 
fection, great  financial  losses,  direct  and  indirect,  and  its  dis- 
turbance of  breeder's  plans. 

Prevalence. — Tuberculosis  is  one  of  the  most  widespread  and 
universal   diseases  affecting  either  humanity  or   domestic   ani- 


FiG.  65. — Bovine  Tubkrculosis.      (M.  H.  B.) 
A  case  showing  plain  symptoms  of  disease.     Rare  type. 

mals.  It  affects  all  of  the  domestic  animals.  Prevalence  is 
greatest  in  the  various  classes  of  animals  in  the  order  named : 
cattle,  hogs,  horses  and  sheep.  Chickens  are  also  quite  sus- 
ceptible to  avian  tubercle  bacilli. 

Cause. — No  fact  in  medicine  is  better  established  than  that 
tuberculosis  is  caused  by  the  Bacterium  of  tuberculosis.  We 
cannot  have  tuberculosis  without  these  germs,  and  it  is  prob- 

192 


TUBERCULOSIS 


193 


able  that  few  people  or  domesticated  animals  can  be  placed  un- 
der continued  exposure  to  the  germs  without  ultimately  hav- 
ing: the  disease.  Predisposing  conditions  undoubtedly  have 
much  to  do  with  its  development — close  confinement,  lack  of 
exercise,  lack  of  ventilation  and  sunshine,  and  injndicious  in- 
breeding, for  instance,  but  these  alone  cannot  cause  it. 

Modes   of  entrance. — Germs  of  tuberculosis  enter   the  body 
(1)    through    the    lungs,    with    inhaled  air;    (2)    through    the 


Fig.  66. — Bovine  Tuberculosis.     (M.  H.  E.) 

A  famous  show  steer,  in  prime  "condition."     Liable  to  be  as  badly  dis- 
eased as  the  preceding. 


Stomach  and  intestines,  with  food  and  drink;  (3)  through 
broken  skin  or  mucous  membrane  by  inoculation;  (4)  by  iiit'cc- 
tion  in  utero,  i.e.,  before  birth.  The  latter  is  of  very  rare 
occurrence  and  of  small  importance. 

Structures  affected. — Tuberculosis  may  affect  almost  any  tis- 
sue or  organ  of  the  body.  Milk  from  tuberculous  cows  may 
be  tuberculous;  but  the  danger  is  especially  great  when  the 
udders  are  affected.  Statistics  indicate  that  about  one  cow  out 
of  every  four  and  six  tenths  (1:4.6)  of  all  tuberculin  reacting 
cows,  give  virulent  milk. 

The  extent  of  tissue  diseased  may  vary  from  a  small  lesion 


194 


VETERINARY  STUDIES 


in  a  small  lymph  gland  to  a  general  invasion  of  lungs,  liver, 
kidneys,  mesenteric  glands,  peritoneum,  and  pleura. 

Sjmiptoms. — These  vary  according  to  extent  and  location  of 
the  disease  and  are  in  general  unreliable  and  indefinite.  A 
few  cases  become  thin  and  rough  in  appearance,  have  a  chronic 
cough  or  chronic  diarrhea,  and  show  general  debility.  The  great 
majority  show  no  symptoms,  and  may  appear  to  be  in  the 
finest    possible   physical   condition.      There   are    a    great   many 


Fig.  67. — Bovine  Tuberculosis.     (M.  H.  E.) 

A  great  variety  of  tubercles  on  the  chest  lining  (costal  pleura).    Sternum 
below,  broken  ribs  above. 


mild  or  latent  cases,  having  but  a  small  amount  of  diseased 
tissue,  and  the  animals  may  live  for  many  years  in  apparently 
good  condition.  On  the  other  hand,  they  may  succumb  to  a 
sudden  development  of  the  disease  following  any  condition 
which  produces  debility. 

When  the  lu7igs  are  involved,  there  may  be  a  loersistent 
cough,  shortness  of  breath,  pallor  of  visible  mucous  membranes, 
loss  of  flesh,  and  unusual  sounds  in  the  lungs. 

When  intestines  and  mesenteric  glands  are  affected,  there 
may  be  chronic  diarrhea  with  slow  and  persistent  loss  of  con- 
dition. All  these  diagnostic  symptoms  may  vary  greatly  and 
are  often  unreliable;  e.g.,  a  cow  may  be  in  good  flesh,  her  hair 


TUBERCULOSIS 


195 


and  eyes  bright,  and  yet  be  extensively  diseased,  and  die  in  a 

short  time. 

Diagnosis.— The  only  reliable  test,  practical  on  a  large  scale 
in  routine  work,  is  tiiborcnlin,  Avhich  is  very  accurate  but  not 

infallible. 

There  are  three  recognized  tuberculin  tests  (see  Lecture 
XL),  all  of  which  are  useful. 

Medical  treatment. — Medical  Ircatinciit  is  not  practical.  It 
is  advisable  to  destroy  or  isolate  diseased  animals  at  once.    Very 


Fig.  68. — Bovine  Tuberculosis.     {M.  U.  E.) 
Tubercles  on  the  great  mesentery. 

valuable  animals  may  be  kept  in  isolation  and  used  for  breed- 
ing purposes  with  good  results  when  considerable  added  expense 
and  work  are  justified. 

Prevention. — Stockmen  should  breed  and  manage  with  a  view- 
to  increasing  physical  vigor.  Bear  in  mind  that  an  animal 
may  have  a  fine  physical  appearance  and  yd  be  easily  sus- 
ceptible to  disease,  if  not  actual  1\    diseased  and  a  spreader. 

The  practice  of  keeping  cattle  almost  continuously  in  the 
stable  does  not  harmonize  with  phun  teachings  of  physiology, 
and  the  results  must  sooner  or  later  l)e  disastrous.  The  great 
law  of  animal  life,  that  use  begets  strength  and  idleness  begets 


196  VETERINARY  STUDIES 

disease,  applies  to  lungs  as  well  as  to  muscles,  and  must  always 
hold  true.  Domestic  animals  cannot  remain  generation  after 
generation  healthy  and  vigorous  without  a  reasonable  amount 
of ■  exercise,  sunshine,  and  fresh  air.  Nature's  laws  cannot  be 
violated  without  paying  an  inevitable  penalty. 

It  is  unwise  to  buy  cattle  for  breeding  purposes  without 
knowing  that  they  are  free  from  tuberculosis  and  this  implies 
first  of  all  dealing  with  an  honest  breeder.  Tuberculin  tests 
of  cattle  from  an  unreliable  breeder  or  jobber  are  of  little  value. 
All  sires — this  is  especially  true  of  cattle — should  have  abun- 
dant exercise  in  open  yards  or  on  treadmills,  or  be  driven  or 
worked.  Ventilation  must  be  thorough,  and  barns  should  be 
constructed  with  a  view  to  allowing  the  entrance  of  abundant 
sunshine.     Sunshine  kills  germs. 

The  student  must  not  gather  from  this  statement  that  a 
herd  may  not  be  badly  diseased  in  an  ideal  stable  if  tuber- 
culosis spreaders  are  put  into  it,  nor  that  good  sanitary  condi- 
tions will  clean  up  a  diseased  herd.  There  is  abundant  proof 
to  the  contrary.  Such  stables  are  safer  and  spread  of  infectious 
disease  must  be  slower  than  where  conditions  are  bad. 

Summary. — Do  not  found  a  herd  with  tuberculous  stock.  Do 
not  introduce  the  disease  while  trying  to  improve  a  herd.  Do 
not  allow  suspicious  animals  in  stable  with  healthy  ones.  Avoid 
close  confinement.  Allow  plenty  of  fresh  air,  exercise,  and 
sunshine  to  breeding  stock. 

All  breeding  cattle  should  be  bought  under  tuberculin  test, 
from  a  sound  herd  and  a  reliable  breeder.  Do  not  buy  even  on 
test  from  a  tuberculous  herd,  or  from  a  herd  that  has  recently 
been  badly  affected. 

Disposition  of  tuberculous  cattle. — Abundant  experiments 
have  demonstrated  that  healthy  calves  can  be  raised  from  tuber- 
culous cows,  and  from  tuberculous  sires.  In  case  of  unusual 
value  or  breeding,  it  is  sometimes  practical  to  free  a  herd  from 
tuberculosis  by  breeding  out  the  disease,  instead  of  by  immedi- 
ately killing  all  diseased  animals.  Animals  which  the  owner 
does  not  think  it  advisable  to  keep  in  quarantine,  at  an  increased 
expenditure  of  time  and  money,  should  be  slaughtered.  It  is 
generally  recognized  that  tuberculous  animals  should  be  slaugh- 
tered under  inspection  and  many  carcasses  should  be  passed  as 
fit  for  food  purposes. 

Tuberculous  cattle  retained  for  breeding  must  be  kept  in  a 


TUBERCULOSIS  197 

separate  stable — preferably  on  a  different  farm.  They  must  not 
be  watered  at  the  same  tank  as  healthy  cattle,  nor  fed  from 
common  mangers.  The  danger  m  allowing  tuberculous  and  non- 
tuberculous  cattle  to  associate  in  the  open  air,  is  less  than  in  a 
stable;  but  this  disease  undoubtedly  spreads  in  the  open  air. 

Accredited  herd  plan. — Every  stockman  should  know  about 
the  accredited  herd  plan. 

This  is  a  common  movement  over  the  United  States  by  which 
state  and  federal  authorities  are  cooperating  to  free  breeding 
herds  from  tuberculosis. 

Such  herds  are  officially  published  as  tuberculosis-free  and 
the  owner  receives  a  certificate  to  this  etfect  from  his  state  and 
the  federal  government. 

Requirements  of  the  ])lan  at  the  present  time  are,  in  general, 
two  negative  annual  tests  or  three  negative  semiannual  tests  of 
the  entire  herd. 

The  owner  first  signs  an  application  and  agreement ;  his  herd 
is  tested  (at  public  expense,  in  some  states),  until  it  becomes 
accredited.  Thereafter  it  must  be  regularly  tested  each  year  by 
a  private  veterinarian  at  the  owner's  expense.  This  veterinarian 
must  have  passed  a  certain  official  examination. 

The  advantages  to  the  breeder  of  being  on  this  list  are  obvi- 
ous: advertising  and  reputation,  shipment  interstate,  advance 
compliance  with  laws  and  regulations  concerning  sale  of  pure- 
bred cattle  for  breeding  purposes,  and  aiding  in  eradication  of 
the  disease  at  the  fountain  source  of  dissemination. 

There  is,  as  a  rule,  more  tuberculosis  among  pure  bred  cattle 
tlian  among  grades,  and  the  general  movement  of  the  pure  bred 
is  from  herd  to  herd  whereas  the  grade  moves  from  farm  to 
killing  floor. 

Fortunately,  the  prevalence  of  tuberculosis  among  pure-bred 
cattle  is  now  being  reduced  and  the  near  future  may  see  the 
figures  reversed  as  between  pure-bred  and  grade  cattle. 

The  following  figures  will  give  the  student  an  appreciation  of 
the  volume  of  this  new  movement  for  accredited  herds.  On  Feb- 
ruary 1,  1922,  there  were  12,157  accredited  herds  in  the  United 
States;  104,467  herds  which  had  had  the  first  negative  test; 
18,956  on  waiting  lists  and  a  total  of  nearly  143,449  under  joint 
state  and  federal  supervision,  ^linnesota  leads  in  clean  herds 
at  this  date  (February  1,  1922)  with  1310  accredited  herds  and 
2256  other  herds  with  first  clean  test. 


LECTURE  XL 
THE  TUBERCULIN  TEST  FOR  TUBERCULOSIS 

Tuberculin  is  usually  seen  in  tablets  or  as  a  straw-colored 
fluid,  slightly  more  viscid  than  water. 

The  active  ingredients  of  tuberculin  are  chemical  products  of 
the  bacilli  of  tuberculosis.  A  certain  broth  is  infected  with  the 
virus  of  tuberculosis,  which  is  allowed  to  multijily  and  grow 
in  this  medium  until  it  has  become  charged  with  the  germ  prod- 
ucts. The  whole  fluid  is  then  heated  to  kill  the  bacteria  and 
filtered  through  porcelain.  Tuberculin  should  therefore  be  not 
only  germ-free,  but  heated  to  a  high  temperature,  and  cannot 
be  infectious. 

Effect  on  cattle. — Careful  experiments  have  demonstrated 
that  tuberculin  has  no  important  effect,  favorable  or  otherwise, 
upon  the  health  or  milk  flow  of  sound  cattle ;  and  that  the  effect 
on  tuberculous  cattle  is  not  objectionable.  An  experiment  was 
conducted  by  the  author  at  the  Minnesota  Experiment  Station 
some  years  ago,  which  included  23  sound  and  5  tuberculous  cows, 
and  compared  the  total  milk  flow  and  total  butter  fat  of  each 
animal  and  of  the  herd  for  the  week  prior  to  test  with  the  week 
of  test.  In  this  experiment  the  cattle  were  given  ordinary 
handling,  neither  very  rough  nor  unusually  gentle. 

There  was  a  moderate  decrease  in  the  milk  flow  during  the 
two  days  of  test,  not  more  than  could  be  easily  accounted  for  by 
unusual  handling  of  the  cattle  and  the  presence  of  strangers. 
This  decrease  was  almost  made  up  during  the  succeeding  five 
days.  There  was  a  slight  increase  of  butter  fat  during  the 
week  of  test.  Both  variations  were  easily  within  the  limits  of 
normal  variation. 

The  experiment  with  the  five  tuberculous  cows  produced  about 
the  same  results,  the  difference  being  easily  within  the  limits  of 
normal  variations,  as  neither  the  total  milk  flow  nor  total  butter 
fat  for  the  entire  week  was  materially  affected  by  the  test. 
Similar  experiments  have  been  made  elsewhere,  the  results  agree- 
ing closely  with  this  general  statement.     It  is  undoubtedly  pos- 

198 


THE  TUBERCULIN  TEST  FOR  TUBERCULOSIS  199 

sible  for  cattle  to  be  so  roughly  handled  during  the  test  that 
the  milk  flow  may  be  seriously  affected ;  but  this  cannot  be 
charged  to  the  tuberculin.  In  cases  where  serious  results  ac- 
company or  follow  tuberculin  tests,  the  disturbance  usually  can 
be  traced  to  some  cause  other  than  tuberculin. 

There  are  three  methods  of  making  tuberculin  tests — the 
thermal  or  subcutaneous,  the  intradermal,  and  the  ophthalmic. 
These  may  be  used  to  good  advantage  in  various  combinations. 
Accuracy. — Averages  of  very  large  numbers  of  animals  tested 
show  tliat  tuberculin  has  a  high  accuracy,  but  is  not  infallible. 
Advanced  cases,  recently  tested  animals,  recently  infected  ani- 
mals, and  certain  latent  and  healed  cases  may  fail  to  give  plain 
reaction.  These  are  all  exceptions ;  in  general,  tuberculous 
cattle  react,  and  the  tests  are  accurate  enough  to  be  thoroughly 
practical. 

Thermal  or  subcutaneous  test. — Any  number  of  animals  up 
to  100  or  so  may  be  included  in  one  test.  These  large  numbers 
can  be  handled  to  advantage  only  by  one  who  is  thoroughly 
familiar  with  the  test,  who  can  use  a  number  of  thermometers, 
and  has  good  assistants.  The  injection  is  usually  made  on  the 
neck,  on  the  flat  of  the  rump,  or  beside  the  tail  head.  A  veteri- 
nary hypodermic  syringe,  holding  10  to  30  c.c.  and  provided 
with  several  short  and  well  sharpened  needles  is  required.  The 
syringe  should  be  first  sterilized  and  kept  clean. 

The  needle  should  be  short,  of  fair  size,  and  inserted  by  sharp 
push  rather  than  a  stab.  Some  cattle  are  inclined  to  kick.  This 
can  usually  be  prevented  if  an  assistant  gives  the  tail  a  vigorous 
pull  sidewise  at  the  right  moment. 

Tivo  periods. — The  time  of  each  test  is  divided  into  two 
periods:  (A)  before,  and  (B)  after  injection.  During  {A)  the 
temperatures  are  taken  e.g.  at  about  8  a.m.,  and  then  again  at  2 
and  4  p.m.  The  tuberculin  is  given  by  hypodermic  injection  at 
10  P.M.  During  (B)  the  temperatures  would  be  taken  at  6,  8,  10, 
and  12  a.m.,  2,  4,  and  sometimes  (i  and  8  p.m. 

The  thermometer. — Self-registering  veterinary  thermometers 
are  necessary  for  the  thermal  test  and  they  slioukl  be  correct 
between  100°  and  105°  F.  Any  thermometer  wliich  varies  one 
half  degree  or  more  from  the  records  shown  by  several  others 
should  be  discarded. 

Temperatures  are  taken  by  inserting  tlie  thermometer  into 
the  rectum  or  vagiiui,  usually  the  former.    If  a  number  of  cattle 


200  VETERINARY  STUMES 

are  being  tested  and  several  thermometers  are  in  use,  the  latter 
are  secured  to  the  tails  for  safety.  This  may  be  easily  done  by 
a  wire  clamp,  rubber  hand,  and  wire  hook,  or  by  shoestrings 
tied  so  as  to  give  the  tail  a  few  inches  of  play.  This  permits  the 
operator  to  use  a  large  number  of  thermometers,  and  prevents 
them  from  falling  to  the  Hoor  and  breaking. 

Dose. — The  dose  is  about  1  c.c.  or  i^  dram  Bureau  tuberculin 
per  300  pounds  live  weight. 

Cautions. — Cattle  must  be  kept  under  the  same  conditions  as 
nearly  as  possible  on  both  days;  i.e.,  watered  at  the  same  hours, 
— immediately  after  a  temperature  never  shortly  before — and 
fed  at  the  same  hours  on  each  day,  given  as  nearly  as  possible 
the  same  amounts,  and  treated  alike  on  the  two  days. 

There  are  many  possibilities  of  error  if  the  operator  is  not 
careful,  accurate,  and  observing.  The  cattle  must  not  be  excited 
or  worried  in  any  way  but  kept  as  quiet  as  possible  during  the 
whole  test.  If  the  whole  stable  or  any  portion  of  it  be  much 
warmer  on  the  second  day  than  on  the  first,  if  any  cattle  are 
allowed  to  become  thirsty  or  drink  large  quantities  of  cold 
water,  or  to  go  much  beyond  their  feeding  time,  note  should  be 
made  of  the  fact  and  this  considered  in  making  the  diagnosis 
in  doubtful  cases.  Drinking  a  large  quantity  of  cold  water  may 
reduce  the  temperature  one  or  two  degrees  at  a  critical  time 
and  spoil  a  low  reaction  in  a  diseased  animal. 

Cattle  that  show  high  temperatures,  above  103,  during  period 
(A)  should  ordinarily  be  released  from  test.  Heavily  pregnant 
cows  may  be  tested  if  carefully  handled  and  temperatures  are 
normal.  It  is  always  possible  that  an  animal  may  show  normal 
temperature  during  (A)  and  then  be  feverish  from  causes  not 
connected  with  the  test,  during  (B).  This  rarely  occurs,  but 
the  possibility  must  be  borne  in  mind. 

Importance  to  hreeders. — The  value  of  the  test  to  breeders  lies 
in  the  fact  that  it  enables  them  to  know  whether  their  cattle  are 
free  from  tuberculosis,  to  free  their  herds  and  put  them  on  a 
sound  and  healthy  basis  in  case  they  are  diseased,  and  to  buy 
safely. 

Diagnosis. — Diagnosis  is  made  mainly  upon  the  fever  reaction. 
If  during  (B)  the  temperature  rises  about  2.5  degrees  or  more 
above  the  highest  normal  as  shown  by  comparison  of  the  (A) 
and  (B)  temperatures,  and  careless  errors  have  been  avoided, 
it  is  usually  safe  to  diagnose  tuberculosis,  providing  the   (A) 


THE  TUBERCULIN  TEST  FOR  TUBERCULOSIS  201 

temperatures  are  not  unusually  low.  To  an  expert  a  rise  of  1.5 
or  less  may  be  a  plain  reaction  in  some  cases  and  only  suspicious 
or  doubtful  symptoms  in  others,  so  that  the  animal  should  be 
held  for  retest  after  60  days.  If  the  normal  temperatures  run 
100°  P.  or  less,  we  would  not  ordinarily  condenni  on  a  2  degree 
rise.     Experience  and  judgment  are  essential  in  this  work. 

A  first  plain  reaction  should  never  be  set  aside  for  a  subse- 
quent negative  retest,  as  the  first  test  is  the  best  and  each  sub- 
sequent retest  in  general  decreases  in  reliability.  Obvious  re- 
actors slioukl  not  as  a  rule  be  retested. 

The  reaction. — The  most  typical  reaction  is  one  wherein  there 
is  gi'adual  rise  and  gradual  decline  of  temperature,  but  many 
plain  reactions  are  not  thus  typical.  Very  abrupt  changes  in 
an  animal's  temperature  should  be  verified  with  a  different 
thermometer.  One  high  temperature  during  (B),  with  the 
others  normal  or  nearly  so,  may  be  only  doubtful  or  suspicious, 
often  it  indicates  an  error  in  the  record.  Animals  that  react 
sometimes  show  diarrhea,  local  swelling  at  the  site  of  injection, 
or  shivering. 

The  intradermal  test. — This  form  of  tuberculin  test  is  a  deli- 
cate operation  requiring  special  skill  and  experience.  It  is 
made  by  injecting  into  the  skin,  usually  in  one  of  the  folds  under 
the  root  of  the  tail,  a  few  drops  of  a  special  tuberculin  with  a 
short  and  very  fine  needle. 

Tuberculous  animals  exhibit  reaction  in  the  form  of  a  per- 
sistent, local  swelling  at  the  site  of  injection.  This  should  re- 
main 72  hours  or  more  after  the  injection  has  been  made. 
Healthy  cattle  may  have  a  temporary  swelling  but  are  nearly 
or  quite  negative  as  a  rule. 

The  intradermal  test  in  skillful  hands  is  probably  as  accurate 
as  the  thermal  test  and  it  has  the  great  advantage  of  greater 
speed  with  regard  to  the  number  of  cattle  that  can  be  tested  by 
an  operator  in  a  given  time.  It  is  therefore  less  expensive  than 
the  thermal  test. 

The  ophthalmic  test. — This  test  is  simpler  in  operation  and 
interpretation  than  the  thermal  and  intradermal  tests;  but  it 
is  less  reliable  for  general  work.  It  is  made  by  putting  special 
ophthalmic  tuberculin  in  the  eye.  This  ophthalmic  tuberculin 
may  be  in  either  tablet  or  liquid  form.  A  double  treatment, 
sensitized  ophthalmic  test,  gives  most  accurate  results.  By  this 
method,  the  same  eye  is  treated  twice,  with  an  interval  of  3  to 


202  VETERINARY  STUDIES 

5  days  between  treatments.  Following  the  second  treatment, 
observations  begin  at  about  the  sixth  hour  and  continue  every 
two  hours  until  about  the  twentieth  hour  unless  plain  reaction 
occurs  in  the  meantime.  Observations  may  also  be  made  after 
the  first  eye  treatment,  if  convenient. 

Tuberculous  cattle  react  with  a  temporary  inflammation  of  the 
eye  structures;  for  example,  hyperemia  of  the  conjunctiva,  pro- 
fuse flow  of  tears,  pus  in  the  eye — usually  at  the  inner  angle — , 
and  sometimes  by  swelling  of  the  lid.  This  reaction  may  be 
slight  or  very  temporary,  and  the  evidence,  such  as  pus,  may  be 
easily  wiped  off  or  lost. 

Any  two  or  all  of  these  three  tests  may  be  used  together  in 
making  a  combination  test.  Any  wise  combination  is  necessarily 
somewhat  more  accurate  than  either  of  the  single  tests,  because 
there  are  a  few  tuberculous  cattle  which  at  any  given  time  will 
respond  plainly  to  one  test  and  not  to  another. 

Combination  tests  should  be  used,  at  least  in  badly  affected 
herds  and  in  herds  of  great  value. 

A  positive  reaction  by  either  test  should  usually  condemn.  A 
suspicious  reaction  by  either  test  should  at  least  isolate  all 
animals  giving  such  suspicious  reactions. 


LECTURE  XLI 
GLANDERS 

The  words  "glanders"  and  "farcy"  refer  to  the  same  disease, 
the  latter  being  commonly  used  for  those  forms  where  the  skin 
and  external  parts  are  especially  affected.  This  disease  is  seri- 
ous because  it  may  be  transmitted  to  human  beings  with  usually 
fatal  results,  and  because  it  results  in  great  loss  in  horses.  It 
is  easily  spread  among  susceptible  animals.  Obscure  cases  may 
be  highly  infections. 

Susceptible  animals.— Glanders  is  practically  confined  to  don- 
keys, mules  and  horses  which  are  susceptible  in  the  order  named. 
Human  beings,  sheep,  and  goats  are  susceptible.  Cattle  are 
immune. 

Causes. — A  minute  rod-shaped  germ  (Bacillus  mallei)  is  the 
direct  and  specific  cause  of  glanders.  Unsanitary  conditions  and 
everything  wliich  lessens  the  animal  vigor  may  act  as  predis- 
posing causes.  The  disease  is  more  severe  and  more  rapidly 
fatal  among  animals  which  are  crowded  or  overworked. 

Incubation. — The  period  of  incubation  varies  greatly.  Dif- 
ferent authors  have  given  it  variously  from  three  to  seven  days 
in  experimental  work;  but  in  natural  cases  it  is  usually  about 
two  weeks. 

Symptoms 

For  our  purpose,  glanders  will  be  divided  into  but  two  types: 
(a)  Respiraiorjj  glanders,  with  or  without  lung  lesions;  and  (&) 
Farcy,  affecting  principally  the  skin  and  superficial  connective 
tissue.  Lung  lesions  may  accompany  either  type.  Acute  and 
chronic  cases  of  each  form  differ  mainly  in  severity  of  symptoms 
and  rapidity  of  development. 

Respiratory  glanders. — Tliis  type  is  characterized  in  general 
by  the  development  of  nodules,  which  change  to  ulcers  on  the 
mucous  membrane  of  the  respiratory  ajiparatus;  by  a  peculiar 
sticky  discharge  from  the  nose;  and  sometimes  by  chronic  cough. 
Certain  lymph  glands  between  the  branches  of  the  lower  jaw 

203 


204 


VETERINARY  STUDIES 


are  affected  in  a  peculiar  way,  becoming  swollen,  tender,  then 
hardened  and  adherent. 

Acute  cases. — In  acute  cases  of  respiratory  glanders,  small 
tubercles  or  nodules  develop  rapidly  on  the  mucous  membrane 
of  the  respiratory  organs  and  soon  change  to  small  ulcers,  which 
increase   in   size    and    even    coalesce.      Thus   is   developed   the 

peculiar  ulcer  of  glanders, 
with  its  dirty  gray  base 
and  overhanging  edges. 
Very  large  ulcers  and  even 
ragged,  gutterlike  excava- 
tions may  develop,  partic- 
ularly on  the  nasal  sep- 
tum. The  ulcers  may 
heal,  leaving  light-colored, 
more  or  less  star-shaped 
scars. 

The  fever  may  be  severe 
in  acute  glanders  of  either 
type,  the  temperature  ris- 
ing rapidly  to  105  or  even 
107,  and  then  be  quite 
variable  for  a  few  days. 
There  may  be  also  per- 
sistent chills. 

There  are  also  areas  of 
lung  inflammation  and 
nodules  in  some  eases.  Oc- 
casionally there  is  an  ap- 
parent recovery  from  the  acute  symptoms  and  then  development  of 
a  chronic  case.  This  condition  applies  to  both  types  of  glanders. 
Chronic  cases. — If  the  disease  be  chronic,  then  in  general  the 
symptoms  develop  less  rapidly  and  the  disease  is  slower  and 
milder.  The  chronic  pulmonary  form  of  glanders  may  be  sus- 
pected when  there  is  a  mild,  dry  cough,  especially  if  such  cough 
be  accompanied  by  debility  and  occurs  in  a  stable  where  an 
obvious  ease  of  glanders  has  been  demonstrated.  When  the 
lungs  are  much  affected  in  chronic  cases  of  pulmonary  glanders, 
the  horse  is  apt  to  show  symptoms  of  heaves,  and  on  examination 
post  mortem  there  are  found  numerous  tubercles,  usually  show- 
ing, or  easily  felt,  on  the  surface  of  the  lungs. 


Fig.  69.— Glanders  (Farcy).  (M.  H.  B.) 

A  recent  case.     Note  the  enlarged  leg 
without  farcy  buds. 


GLANDERS 


205 


A  horse  may  he  affected  with  a  mild,  chronic  form  of  the 
disease  and  remain  in  good  flesh,  he  vigorous  and  apparently  in 
the  hest  of  health  for  years,  showing  no  marked  nasal  discharge 
or  farcy  sores,  and  yet  be  very  actively  infectious  to  other 
horses. 

Chronic    eases   may   show   a   chronic    nasal   discharge,    nasal 
ulcers,  and  hardened,  ad- 
herent    maxillary     glands 
and  unthrift. 

Farcy. — In  the  farcy 
form  of  glanders  the  su- 
perficial connective  tissues 
and  Ij-mph  vessels  and 
glands  are  especially  in- 
volved. 

In  the  acute  farm,  there 
is  high  temperature  and 
local  swellings.  These 
swellings  often  occur  on 
one  or  both  hind  legs.  As 
the  swellings  abate,  the 
characteristic  nodules,  or 
farcy  buds,  appear. 

The  head  may  swell 
badly  and  farcy  sores  ap- 
pear later  at  irregular  in- 
tervals and  places.  Farcy 
buds  tend  to   heal  slowly 

and  leave  scars  as  shown  in  Fig.  71.     When  farcy  buds  break, 
there  is  discharged  a  clear,  viscid  pus  that  is  very  characteristic. 

The  specific  symptoms  of  farcy  may  be  summed  up  as  the  hud, 
the  ulcer,  the  lymphatic  cord,  and  the  characteristic  viscid,  sticky 
discharge. 

In  the  chronic  form  we  have  similar  histories  and  symptoms, 
but  the  latter  are  less  obvious  and  develop  less  rapidly. 

Diagnosis. — A  positive  diagnosis  on  the  clinical  symptoms  may 
be  frequently  made.  P>nt  there  are  a  great  many  cases  which 
cannot  be  so  diagnosed  with  certainty.  Some  show  indefinite 
symptoms  and  others  show  none.  In  such  cases,  we  must  rely 
upon  mallein  tests  of  which  we  now  have  three. 

Mullein  tests. — The  temperature  test  is  conducted  as  follows: 


1^'iG.  70. — Glanders  (Farcy j.  {M.  H.  E.) 

An  old  case.     Note  enlarged  leg  with 
old  farcy  buds,  healed. 


206 


VETERINARY  STUDIES 


Temperatures  are  taken  at,  e.g.,  10  a.m.,  2  p.m.  and  6  p.m.  The 
mallein  is  then  given  by  a  hypodermic  injection  at  about  10 
P.M.  On  the  following  day  temperatures  are  taken  every  two 
hours,  beginning  at  6  a.m.  and  continuing  until  6  or  8  p.m.  or 
even  later  if  the  temperature  is  rising  and  the  reaction  is  indefi- 
nite. A  rise  of  three  degrees  or  more  above  the  high  normal  to 
104  or  higher  is  diagnostic,  and  usually  means  glanders.     Such 

a  rise  of  temperature  is  spoken  of  as  a 
reaction.  Reacting  animals  usually  show 
a  prominent  and  painful  swelling  at  the 
point  of  injection — an  important  con- 
sideration in  the  diagnosis. 

This  test  is  being  superseded  by  the 
newer  and  simpler  tests. 

The  second  mallein  test,  the  intrader- 
mal, is  made  by  injecting  a  special  mal- 
lein with  a  fine  needle  into  the  skin  of 
the  lower  eyelid.  The  glandered  horse 
reacts  with  an  inflammation  and  per- 
sistent swelling  at  the  point  of  injection. 
The  third  mallein  test,  the  ophthalmic, 
is  made  by  placing  a  special  tuberculin 
in  the  eye.  The  glandered  horse  reacts 
by  inflammation,  and  pus  in  the  eye, 
usually  at  the  inner  angle. 

Mallein  has  revealed  the  rather  serious 
fact  that  there  are  unquestionably  many  cases  of  glanders  which 
are  never  recognized,  some  of  them  without  doubt  infectious. 

Prevention. — The  common  methods  of  spread  must  be  borne 
in  mind,  and  the  fact  be  clearly  realized  that  the  germ  which 
causes  glanders  is  very  easily  disseminated. 

Some  of  the  more  common  mediums  of  spreading  it  are  drink- 
ing water,  feed  boxes  and  troughs,  hitching  racks  and  posts, 
and  public  water  fountains,  which  should  be  abolished  and  re- 
placed by  individual  pails.  Any  means  which  serves  to  bring 
the  virus,  B.  mallei,  into  direct  contact  with  mucous  membranes 
or  with  the  broken  skin  may  be  sufficient  to  cause  the  disease. 
Pus  from  the  farcy  sores  and  the  nasal  discharge  are  very 
virulent. 

Prevention  therefore  consists  in  avoiding  conditions  which 
may  bring  the  virus  into  contact  Avith  the  mucous  membranes 


Fig.      71.- 
(Farcy). 


-G-  L  A  N  D  E  R 

(M.  E.  B.) 


Farcy  sears  in  the  face. 
An  old  case. 


GLANDERS  207 

or  brokoii  skin.  It  is  never  safe  to  purcliase  from  a  stranpjer,  a 
horse  that  lias  nasal  discharge  or  suspicious  sores.  Stories  of 
having:  caught  cold  or  a  "little  distemper"  may  usually  be  sus- 
pected, under  such  circumstances. 

Treatment. — It  is  probable  that  some  cases  of  glanders  recover 
under  favorable  conditions  without  treatment,  especially  in  the 
Northwest ;  but  the  disease  is  dangerous  and  we  have  no  means 
of  knowing  which  cases  have  a  reasonable  probability  of  re- 
covery, for  medical  treatment  by  the  use  of  drugs  is  not  re- 
liable. For  these  reasons  treatment  of  glanders  is  not  justified. 
All  cases  should  be  reported  to  the  proper  health  officers. 

Suggestions. — In  many  states  it  is  wisely  made  a  punishable 
ofifense  to  water  a  glandered  horse  at  any  public  watering  place, 
hitch  it  to  a  public  rack  or  post,  or  place  it  in  a  public  barn. 

All  plain  cases  should  be  killed  and  all  exposed  horses  and 
mules  should  be  tested  with  mallein. 

Reactors  should  usually  be  killed,  whether  showing  symptoms 
or  not. 

In  some  states,  OAvners  receive  state  reimbursement  for  glan- 
dered horses  killed  by  order  of  the  state. 


LECTURE  XLII 
HOG  CHOLERA 

To  be  considered  hog  cholera,  the  disease  must  be  infectious 
by  pen  exposure,  and  an  attack  followed  by  recovery  must  give 
immunity ;  the  blood  from  a  diseased  hog  should  be  virulent  and 
capable  of  reproducing  the  disease ;  the  living  animal  should 
show  the  symptoms  later  described ;  and  the  carcass  of  the  dead 
animal  should  show  the  symptoms  given  under  {lutopsy. 

Variations  in  virulence. — Outbreaks  of  hog  cholera  vary 
greatly  in  virulence  and  symptoms.  In  some  outbreaks  the 
virulence  is  marked,  and  the  hogs  die  quickly ;  in  others  a  ma- 
jority of  the  cases  assume  the  chronic  type,  the  hogs  do  not  die 
so  quickly,  and  the  percentage  of  loss  is  not  so  gi-eat. 

Various  gradations  may  appear  between  cases  of  the  utmost 
virulence  and  those  of  the  milder  type. 

General  symptoms. — Lack  of  appetite,  fever,  and  thirst  are 
early  symptoms  of  hog  cholera.  The  hair  becomes  harsh  and 
dry,  the  eyes  may  be  watery,  and  the  gait  becomes  weak  and 
irregular,  with  imperfect  control  of  the  hind  legs.  The  skin 
around  the  flanks  and  fore  legs  and  abdomen  may  become 
purple ;  that  of  the  ears  frequently  becomes  much  inflamed,  and, 
if  the  hog  lives  for  several  days,  may  assume  a  scabby  appear- 
ance. Sometimes  the  tips  of  the  ears  slough  off.  The  sick  hogs 
soon  separate  themselves  from  the  rest  of  the  herd,  being  dis- 
posed to  hide  in  sheltered  places,  and  are  little  inclined  to  move 
about.  Chronic  cases  lose  flesh  rapidly  and  sometimes  show 
extreme  disturbance  of  the  nervous  system,  exhibited  in  partial 
or  complete  paralysis  of  the  hind  parts,  or  extreme  nervousness. 
The  cough  is  usually  short  and  hacking.  Occasional  constipa- 
tion appears  among  the  earliest  symptoms,  but  is  usually  not 
noticed ;  later,  diarrhea  appears.  In  some  of  the  very  acute 
eases  which  appear  at  the  beginning  of  an  outbreak,  the  animals 
die  very  suddenly — sometimes  before  the  owner  realizes  that 
they  are  sick.  Later  in  the  history  of  the  disease,  as  it  appears 
in  a  herd,  the  cases  tend  to  assume  the  more  chronic  type. 

208 


HOG  CHOLERA  209 

At  times  quite  large  portions  of  skin  and  underlying  muscu- 
lar tissue  die  and  slough  off,  leaving  large  sores.  These  sores 
appear  more  commonly,  perhaps,  around  the  neck,  head,  and 
back  than  elsewhere.  This  is  probably  not  due  to  the  filterable 
virus  but  to  secondary  invaders. 

Farmers  must  bear  in  mind  that  symptoms  vary  greatly  in 
different  outbreaks,  and  avoid  being  led  into  tlie  costly  error  of 
mistaking  mild  cholera  for  something  else.  It  is  not  always 
easy  even  for  an  expert  to  diagnose  cholera,  and  for  this  reason 
it  is  safer  to  assume  that  a  questionable  outbreak  is  cholera. 


Fig.  72. — Hog  Cholera.     (M.  H.  E.) 

Subcutaneous  heinorihages  resembling  those  of  hemorrhagic  septicaemia. 
Note  the  dark  spots. 

Autopsy. — The  skin  on  parts  of  the  body  where  the  hair  is 
thin,  like  the  Hanks  and  inside  of  the  fore  legs  and  thighs,  may 
be  deep  red  or  purple.  Hemorrhages  may  be  usually  found  in 
the  fatty  tissue  under  the  skin  and  on  the  internal  organs.  The 
lungs  often  show  scattered  and  sharply  defined  areas  which  are 
dark  in  color,  solid  and  much  like  liver.  Or,  there  may  be  a 
severe  general  pneumonia  with  pleurisy.  The  lymph  glands  in 
the  mesentery  and  elsewhere  are  deeply  hyperemic  or  hem- 
orrhagic. 

When  the  large  intestine  is  opened,  dark  spots,  more  or  less 
bloodstained,  or  even  clots  of  blood,  may  be  seen  upon  tlic  lining 
membrane  when  the  disease  is  of  a  very  acute  type.  The  more 
chronic  cases  show  peculiar  and  characteristic  ulcers  in  the  lin- 
ing membrane  of  the  digestive  tract,  especially  the  large  intes- 
tine, and  they  are  usually  more  numerous  near  the  cecum  or 
blind  pouch.  These  ulcers  are  irregular  in  outline,  with  yellow- 
ish or  dark  centers,  and  frequently  appear  as  being  raised  above 


210 


VETERINARY  STUDIES 


the  surface.     Small  ulcers  may  occur  in  the  back  part  of  the 
mouth,  in  the  gullet  and  stomach. 

Very  small  hemorrhages  are  found  on  the  surface  or  through 
the  deeper  structure  of  the  kidneys. 

Cause. — Hog  cholera  is  a  very  infectious  disease  which  has 
its  origin  in  a  living'  virus.  The  virus  particles  are  probably 
so  small  as  to  be  invisible  with  our  best  microscopes  and  are 
capable  of  passing  in  some  form  through  a  laboratory  germ 
filter. 

This  is   probably   a  complicated   disease   in   most   outbreaks. 

The  filterable  virus  is  evidently 
the  principal  and  specific  infec- 
tion. With  this  virus  there  is 
usually  one  or  more  secondary 
invaders.  One  of  the  secondary 
invaders  may  cause  or  con- 
tribute to  the  chronic  lesions, 
ulcers  of  the  digestive  tract,  for 
instance.  Another  may  cause 
or  contribute  to  the  lung  and 
pleura  lesions.  This  accounts, 
in  part,  for  the  wide  variations 
in  symptoms  and  lesions. 

Infection  usually  occurs  by 
way  of  the  mouth,  and  the 
period  of  incubation  is  from  8 
to  14  days.  Simple  conditions  of  keep  and  feed  have  much  to  do 
with  making  the  animals  susceptible,  but  food  and  surroundings 
cannot  serve  as  the  first  cause  of  hog  cholera.  Predisposing 
factors  must  be  given  due  consideration,  but  the  most  important 
things  to  remember  are  the  sick  hog  and  the  living  virus  and  that 
hog  cholera  never  appears  without  the  infection  which  may  be 
easily  carried  from  one  place  to  another. 

If  the  hog  is  fed  exclusively  on  corn  diet  and  kept  overfat ; 
or  if  it  is  kept  shut  up  in  dark,  damp,  and  perhaps  filthy  pens, 
it  will  not  be  able  to  resist  any  disease  as  would  the  hog  kept 
under  more  favorable  conditions.  But  these  are  only  contribut- 
ing factors.  The  laws  of  hygiene  cannot  be  neglected  without 
rendering  any  animals  more  susceptible  to  disease ;  but  no  de- 
gree of  ordinary  vigor  can  give  assurance  of  immunity  to 
cholera. 


Fig.  73. — Hog  Cholera. 
(M.  H.   B.) 

Hemorrhages  (dark  spots)  on 
iliapliragin.  Hemorrhages  are  char- 
acteristic. 


HOG  CHOLERA 


211 


How  scattered. — The  virus  of  this  disease  may  be  carried  from 
place  to  place  in  any  way  that  very  fine  particles  of  heavy  dust 
may  be  carried,  e.g.,  by  people,  upon  shoes,  or  by  Avagons  or  stoe-k 
cars.  Dogs  are  frequent  carriers  of  the  tlisease.  Running 
streams  and  shallow  lakes  are  serious  factors  in  its  spread. 
Bowel  discharges  are  very  important  sources  of  infection^  and, 
if  yards  or  pens  drain  into  streams  or  lakes,  water  tlien  becomes 
the  carrier  of  infection.     Hogs  that  have  died  of  cholera  are 


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Fig.  74.— Hog  Cholera.     (M.  H.  E.) 

Large    intestine;    mucous    membrane    showing    general    distribution    of 
typical  ulcers.     /,  Ileum;   C,  caecum  or  blind  pouch. 


sometimes  thrown  into  streams  or  buried  in  sand  near  the  edge 
of  a  stream  or  lake,  thus  infecting  the  water. 

Hog  cholera  virus  may  live  many  months;  around  strawstacks 
and  old  sheds  under  favorable  conditions. 

When  an  outbreak  appears.— In  cas<>  ihere  is  a  suspicious 
disease  among  hogs,  the  matter  should  be  reported  promptly  to 
health  officers  so  that  this  first  outbreak  may  be  i)roniptl,y  and 
rigidly  (luarantined  and  the  hogs  vaccinated.  If  reliable  serum 
for  vaccination  is  not  available  then  but  one  person  should  have 
the  care  of  a  herd  of  healthy  hogs,  and  should  not  be  allowed  to 
go  where  there  is  possibility  of  carrying  the  infection  on  shoes, 


212  VETERINAEY  STUDIES 

for  example.  No  member  of  the  family  should  go  to  any  farm 
where  swine  disease  has  appeared ;  nor  should  any  one  from  the 
farm  where  such  sickness  is  present  be  allowed  to  walk  about 
the  yards  of  his  neighbor.  Dogs  and  other  dangerous  visitors 
should  be  kept  away  from  the  pens  on  uninfected  farms  by  a 
temporary  fence  if  necessary. 

Hogs  should  not  be  allowed  access  to  small  ponds  or  mudholes 
during  the  prevalence  of  any  suspicious  disease.  Such  ponds 
and  mudholes  become  deadly  centers  of  infection. 

Before  a  herd  becomes  infected,  it  may  be  desirable  to  divide 
it  into  three  or  four  parts,  if  serum  is  not  available,  and  sepa- 
rate these  groups  widely  on  different  portions  of  the  farm.    The 


Fig.  75.— Hog  Cholera.     (M.  H.  E.) 

Ulcers  in  mucous  membrane  of  large  colon.  Bowel  split  open.  View  of 
the  interior. 

owner  may  then  lose  one  group,  or  even  two  groups,  and  still 
save  the  others. 

If  the  weather  is  cool  or  wet,  the  herd  should  be  given  quar- 
ters as  warm  and  dry  as  possible,  because,  under  conditions  of 
exposure,  the  mortality  is  apt  to  be  very  high. 

So  far  as  we  know  now  it  is  useless  to  spend  money  on  medi- 
cines in  the  treatment  of  hog  cholera  and  before  giving  credit 
to  patent  medicines,  one  should  bear  in  mind  that  outbreaks 
often  check  suddenly  without  treatment. 

Experience  demonstrates  that  it  is  desirable  to  luove  the 
healthy  animals  away  from  the  sick  promptly,  if  serum  is  not 
available,  and  to  place  them  in  uninfected  sheds,  pens,  or  yards. 
It  is  also  important  to  keep  the  pens,  both  where  the  sick  and 
the  healthy  hogs  are  confined,  thoroughly  cleaned  and  frequently 
disinfected.  For  cleansing  and  disinfecting  purposes,  unslaked 
lime  used  freely  is  satisfactory,  and  easily  applied.  The  better 
grades  of  coal-tar  disinfectants  are  also  satisfactory. 


HOG  CHOLERA  213 

Hog"  cholera  vaccination. — The  Dorset-Niles  serum  is  now 
freely  available  and  is  reliable  when  properly  nsed.  The  method 
of  produeing  this  serum  is,  in  general,  as  follows: 

A  hog  that  is  immune  by  reason  of  having  ])assed  through 
the  disease  or  having  been  vaeeinated  is  given  a  large  quantity 
of  virulent  hog-eholera  serum,  llis  own  blood  then  develops  a 
property  which  protects  other  hogs  when  it  is  injected  under 
the  skin  or  into  muscular  tissue.  The  serum  of  this  hog's  blood 
produces  a  prompt  but  temporary  immunity.  If  the  hog  which 
has  received  such  serum  be  given  pen  exposure  with  sick  hogs, 
or  an  injection  with  a  small  quantity  of  virulent  blood  (simul- 
taneous vaccination),  it  then  becomes  rather  permanently  im- 
mune, for  it  has  had  the  disease  in  a  mild  form  and  recovered. 
There  are,  therefore,  two  ways  of  vaccinating  by  the  Dorset- 
Niles  method :  serum  only,  which  gives  prompt  but  temporary 
immunity;  and  simultaneous  vaccination,  which  gives  perma- 
nent immunity.  The  dose  of  serum  varies  according  to  the 
weight  of  the  hog  treated.  Serum  should  be  kept  unopened 
and  cool  until  used,  and  all  precautions  should  be  taken  to  insure 
clean  work  in  vaccinating. 

There  are  other  useful  fields  for  this  vaccine :  Owners  may 
wish  to  vaccinate  valuable  hogs  in  advance  of  any  possible  out- 
break, or  exposure  to  disease  at  stock  shows.  Another  and  per- 
haps the  most  important  field  relates  to  outbreaks  of  the  disease 
where  vaccine  can  be  used  early  iii  an  outbreak  to  prevent  or 
lessen  losses  and  thus  protect  surrounding  herds  and  check  the 
outbreaks. 

Common  mistakes. — It  is  a  mistake  to  bury  hogs  that  have 
died  of  cholera  when  the  carcasses  can  be  burned,  for  burning 
is  by  far  the  most  ef^cient  means  of  destroying  the  germs  of 
such  diseases.  If  it  is  not  convenient  to  burn  the  carcasses,  they 
should  be  buried  under  at  least  four  feet  of  earth  and  covered 
freely  with  fresh  lime. 

It  is  a  mistake,  and  frequently  a  serious  one,  for  a  farmer  to 
ship  in  strange  hogs  from  stockyards,  and  put  these  with  stock 
hogs  already  on  hand  without  vaccination  or  quarantine.  The 
mere  fact  that  the  hogs  came  from  an  uninfected  district  is  no 
argument  to  the  contrary,  for  the  car  in  which  they  were  shipped 
may  have  recently  carried  hog-cholera  victims.  New  breeding 
stock  should  usually  be  isolated  for  three  weeks  before  putting 
them  with  hogs  already  on  the  place  unless  the  latter  be  immune. 


214  VETERINARY  STUDIES 

This  allows  time  for  the  disease  to  appear  in  case  the  new  hogs 
have  come  from  infected  herds,  through  infected  stockyards,  or 
in  infected  cars. 

It  is  a  mistake  to  visit  your  neighbor's  hogpens,  and  walk 
about  among  the  hogs  out  of  mere  curiosity,  when  your  neigh- 
bor has  told  you  that  some  peculiar  sickness  has  appeared  in 
his  herd. 

It  is  a  mistake  to  allow  the  last  one  or  two  sick  hogs,  which 
usually  show  a  very  chronic  type  of  the  disease,  to  linger  for 
months  on  the  farm.  It  is  a  better  policy  to  kill  such  hogs 
promptly,  and  have  done  with  the  disease.  They  do  not  usually 
become  thrifty  and  profitable  feeders  for  a  long  time  after  re- 
covery. On  the  other  hand,  they  may  remain  infectious  to  the 
last  period  of  their  sickness,  thus  keeping  the  yards  and  pens 
infected  and  furnishing  a  supply  of  infectious  material  for 
future  outbreaks. 

It  is  a  criminal  mistake  to  leave  carcasses  in  gullies,  or  throw 
carcasses  into  any  stream,  lake,  or  pond,  or  to  bury  them  near 
such  body  of  water. 

SuggestioTi. — An  outbreak  of  hog  cholera  may  be  quarantined 

when  it  first  appears;  but  it  is  extremely  difficult  to  quarantine 

the  disease  after  it  has  been  scattered  over  several  townships. 

Quarantine  to  be  effective  must  be  prompt  and  rigid ;  partial  or 

imperfect  quarantine  is  worse  than  useless. 

iJisinfection. — The  virus  may  live  for  months,  under  favor- 
able conditions.  Sometimes  the  cheapest  way  to  disinfect  is  to 
burn  old  sheds  and  pens  where  the  siclc  hogs  have  been  con- 
fined. But  if  these  structures  are  valuable,  other  means  of  dis- 
infection must  be  considered.  Corrosive  sublimate,  dissolved 
in  water  in  the  proportion,  of  7.5  grains  to  each  pint,  is  a  good 
disinfectant ;  or,  whitewasli  that  is  made  by  adding  fresh  chlorid 
of  lime,  one  half  pound  to  the  gallon,  may  be  used  instead  of  the 
corrosive  sublimate  solution.  All  bedding  and  loose  stuff  should 
be  burned  or  plowed  under.  The  gi'ound  may  be  disinfected 
by  saturating  the  surface  with  corrosive  sublimate  solution,  or 
by  burning  off  straw  that  lias  been  scattered  over  the  surface, 
and  the  danger  of  infection  may  be  lessened  by  plowing  and 
planting  the  infected  area. 


LECTURE  XLIII 
COMMON  MINOR  DISEASES  OF  SWINE 

Posterior  Parx\lysis 

Posterior  paralysis  is  a  rather  conmion  and  serious  condition 
affecting  swine;  it  involves  tlie  hind  quarters,  and  is  probably  a 
symptom  of  several  different  disorders.  In  some  cases  it  is 
probably  a  disorder  of  the  spinal  cord ;  in  others,  there  is  weak 
bone  due  to  poorly  balanced  diet.  Still  others  are  due  to  injury 
inflicted  b}'  other  stock,  etc.  Fracture  of  the  femur  or  other 
leg  bones' sometimes  occurs  in  connection  with  rachitis  (rickets), 
and  is  mistaken  for  paralysis.  Rachitis  may  appear,  like  pa- 
ralysis in  growing  swine.  Some  cases  are  due  to  injury  of  the 
spinal  cord.  Paralysis  often  appears  in  heavy  hogs  after  ship- 
ment by  rail.  Other  cases  are  due  to  slow  organic  disease  of  the 
spinal  cord,  the  direct  cause  of  which  is  not  known.  A  common 
type  of  posterior  paralysis  develops  suddenly  in  old  and  heavy 
swine,  particularly  those  in  high  flesh,  and  is  due  to  simple 
constipation. 

Symptoms. — Some  cases  develop  suddenly;  others  gradually. 
Those  wliicli  develop  slowly  show  at  first,  irregular  gait  behind. 
The  legs  cross  in  walking;  there  is  dil^culty  in  rising  and  a 
general  lack  of  control  for  the  hind  legs. 

If  the  case  develops  suddenly,  there  is  inability  to  use  the 
hind  limits,  which  are  limp  and  weak — not  unlike  affected  limbs 
of  horses  having  azoturia.  Hogs  affected  with  this  trouble  often 
retain  good  appetite  and  are,  apparently,  in  good  health  for 
weeks,  having  perfect  control  of  the  front  limbs.  If  they  move 
at  all,  Ihe  liind  limbs  are  dragged. 

Treatment. — For  the  heavy  hog  lacking  in  exercise,  give  a 
decided  pliysic,  10  to  20  grains  of  calomel  or  else  two  compound 
cathartic  i)ills  in  a  small  piece  of  pork;  or  2  oz.  castor  oil.  The 
rachitic  form  in  young  hogs  is  prevented  by  feeding  skim  milk, 
tankage,  etc.,  and  giving  more  exercise. 

21.", 


216  VETERINARY  STUDIES 

Congestion  op  the  Lungs 

Congestion  of  the  lungs  is  essentially  an  engorgement  of  the 
pulmonary  blood  vessels,  often  caused  by  active  exercise  of 
swine  in  high  flesh. 

Symptoms. — These  cases  are  usually  acute  and  are  likely  to 
end  fatally.  The  symptoms  are  those  of  suffocation.  There  is 
marked  distress  and  hurried  respiration,  the  mouth  being  held 
open  in  an  effort  to  get  air.  The  pulse  is  rapid  and  weak,  and 
the  animal  is  apt  to  fall  suddenly. 

On  examination  post  mortem  the  pulmonary  vessels  arc  found 
engorged  and  the  lungs  dark. 

Treatment. — If  the  condition  of  the  hog  permits,  use  a  stimu- 
lant :  aromatic  spirits  ammonia  1  to  2  drams,  alcohol  4  drams, 
in  water,  repeated  at  short  intervals ;  for  example,  15  minutes 
to  one  half  hour.  The  animal  must  be  kept  warm  and  the  ex- 
tremities rubbed  vigorously.  Extreme  care  is  necessary  in  giv- 
ing liquid  medicines  in  these  cases  to  avoid  killing  the  animal 
by  suffocation.     Hypodermic  stimulants  are  safer. 

Constipation 

Constipation  is  a  rather  frequent  cause  of  trouble  among 
swine. 

Cause. — This  trouble  is  very  frequently  associated  with  high 
feeding  and  lack  of  exercise,  especially  when  the  food  is  dry 
and  lacking  in  laxative  material.  It  rarely  aff'ects  hogs  when 
on  grass,  clover,  roots,  pumpkins,  or  other  fresh  vegetables. 

Symptoms. — The  aft'ected  hog  is  restless,  and  occasionally 
strains  as  though  trying  to  pass  manure;  its  manure  is  hard 
and  frequently  covered  with  mucus^  and  the  hog  becomes  dull 
and  loses  appetite. 

Treatment. — Give  1  to  3  ounces  of  castor  oil,  depending  on 
the  size  of  the  hog,  or  as  a  substitute  for  the  oil  give  Epsom 
salts,  in  1  to  3  ounce  doses  dissolved  in  warm  water  and  admin- 
istered as  a  drench.  For  mild  cases  of  simple  constipation,  old- 
fashioned  senna  tea,  with  rectal  injections  of  warm  water,  is 
usually  very  satisfactory. 

It  is  necessary  to  exercise  great  caution  in  giving  liquid 
medicine  to  hogs  lest  they  be  suffocated  by  drawing  liquid  into 
the  lungs  while  squealing. 


COMMON  MINOR  DISEASES  OF  SWINE  217 

A  very  simple  method  of  drenching  swine  is  to  cut  a  hole  in 
the  toe  of  an  old  shoe ;  insert  the  toe  into  the  month,  and  allow 
the  hog  to  chew  it  while  the  medicine  is  ponred  in  slowly  and 
carefully.  A  short  piece  of  ordinary  garden  hose  with  a  funnel 
inserted  at  one  end  is  also  very  satisfactory  for  this  purpose. 
Or,  put  a  piece  of  rubber  hose  on  the  neck  of  bottle,  give  medi- 
cine slowly  and  cautiously  and,  if  possible,  when  the  animal  is 
not  squealing.  The  animal  may  either  be  thrown  down  and 
held,  or  tied.  A  loop  may  be  passed  around  the  upper  jaw  back 
of  the  front  teeth  and  held  by  a  turn  around  a  post,  but,  in  this 
case,  medicines  must  be  given  with  great  care. 

Black  teeth. — Hlack  teeth  in  young  pigs  are  not  of  serious 
importance  so  far  as  the  teeth  are  concerned. 


DIETETIC  DISEASES 

LECTURE  XLIV 
AZOTURIA 

Prevalence. — Azoturia  is  a  common  and  very  serious  disease 
Avhicli  nsually  affects  horses  under  certain  well-defined  condi- 
tions. It  affects  the  best  and  most  valuable  horses  and  is  fre- 
quently fatal.  Farm  horses  in  the  North  do  comparatively  little 
work  during  the  winter,  and  are  in  high  tiesh  when  early  spring 
work  opens.  This  condition,  together  with  the  fact  that  the 
early  spring  is  necessarily  a  season  of  irregular  work,  will  ex- 
plain why  so  many  cases  of  azoturia  occur  during  the  spring 
months. 

History. — Azoturia  rarely  appears  among  horses  at  pasture 
or  among  those  at  regular  work.  It  usually  appears  dur- 
ing exercise  after  a  period  of  idleness,  on  full  feed  which 
has  succeeded  a  previous  period  of  work.  Any  severe  exertion 
after  an  idle  period  may  cause  it,  e.g.,  struggling  in  the  casting 
harness  or  when  halter-cast  in  the  stall. 

This  disease  is  frequently  confounded  with  colic;  sometimes 
farmers  call  it  spinal  disease,  and  sometimes  an  inflammation 
of  the  kidneys ;  but  it  is  easily  distinguished  from  any  of  these 
by  its  history — which  is  very  uniform — ^by  the  symptoms  and 
by  the  condition  of  the  urine. 

Duration. — Ordinary  cases  begin  to  either  recover  or  fail 
within  three  or  four  days.  The  more  severe  cases  may  either 
die  in  a  few  days  or  develop  a  persistent  and  more  or  less  com- 
plete paralysis  of  the  hind  quarters  and  limbs  lasting  weeks  or 
even  months. 

Causes. — The  causes  of  azoturia  are  classified  as  predisposing 
and  precipitating. 

The  predisposing  causea  include  high  flesh,  diet  rich  in  pro- 
teid,  and  full  feed  during  a  period  of  rest  following  a  period 
of  regular  work.  Most  cases  appear  during  the  prime  of  life. 
]\Iares  are  more  frequently  affected  than  geldings,  but  all  horses 
are  subject  to  azoturia. 

218 


AZOTURIA  219 

The  precipitating  factor  is  active  exercise,  following  idleness 
on  full  feed. 

Symptoms. — The  symptoms  appear  suddenly,  with  little  or  no 
warning?,  and  are  very  unifoi-m.  The  horse  comes  out  of  the 
stable  fecliii<2:  unusually  well,  tlien  after  ji:oinf]^  a  short  distance 
goes  suddenly-  lame,  or  stiff,  or  weak,  in  his  hind  legs.  Both 
legs  may  be  affected  alike,  or  one  only,  or  one  first,  then  the 
other.  Occasionally  one  or  both  front  limbs  are  affected.  The 
horse  staggers,  is  very  weak  on  his  affected  legs,  and  may  fall 
before  he  can  be  unhitched. 

He  perspires  very  freely ;  the  muscles  over  his  loins  and  hips 
are  rigid  to  the  touch,  frequently  tender  on  i)ressure,  and  may 
tremble  or  twitch. 

The  urine  is  highly  colored,  varying  from  red  to  almost  l)laek, 
and  increased  in  specific  gravity.  This  abnormal  color  is  due 
to  the  presence  of  red  coloring  matter  of  the  blood  and  volun- 
tary muscles.  It  may  not  be  conspicuous,  however,  in  mild 
cases.  Th(>  pulse  may  run  up  to  (iO  oi-  80  per  minute  (normal, 
42  to  48)  ;  and  the  temperature  increase  to  102  or  104  (normal 
about  101)  if  the  animal  is  restless,  l)ut  in  many  cases  they  vary 
but  little  from  normal.  The  bowels  may  be  normal,  and  the 
appetite  fairly  good  in  mild  cases.  Skin  sensation  may  be  di- 
minished, as  shown  by  pricking  with  a  }un.  The  natural  peris- 
taltic action  of  the  intestines  may  be  suppressed,  but  the  bowels 
will  usually  empty  under  the  influence  of  an  injection  or  other 
local  irritation.  A  chronic  paralysis  affecting  one  or  both  hind 
limbs  may  be  a  troublesome  factor  in  the  case. 

Prevention. — Prevention  is  simple,  easily  applied,  inexpen- 
sive and  reasonably  certain,  and  for  these  reasons,  preferable 
to  treatment,  which  is  frequently  unsatisfactory  even  if  the  pa- 
tient recovers.  Moreover  one  attack  predisposes  to  another,  and 
the  second  attack  is  more  easily  brought  on  than  the  first.  Pre- 
venting tlie  first  attack  may  j)rev('nt  several  attacks  and  ulti- 
mate death  of  tlie  horse. 

There  is  but  slight  danger  of  azoturia  for  the  horse  tlial  is 
thin  and  weak,  or  for  the  young  colt  or  for  the  aged  horse.  This 
disease  often  affects  the  best  horse  in  the  barn,  one  that  is  in 
good  flesli  and  in  the  ])rime  of  life.  AVhen  such  a  horse  has 
been  working  on  full  feed  for  ;i  lime  and  tlien  stands  idle  for  a 
few  days,  or  even  twenty-four  iioui-s,  make  a  large  reduction  in 
the  grain  ration,  or  if  tlie  horse  is  (|uite  fat,  stop  all  the  grain. 


220  VETERINARY  STUDIES 

A  fat  horse  needs  but  little  grain  when  standing  idle.  If  he  has 
worked  recently,  allow  him  plenty  of  water  and  turn  him  loose 
in  the  yard  or  exercise  him  every  day  if  possible.  If  the  grain 
has  not  been  reduced  as  it  should  have  been  while  the  horse  was 
idle,  the  next  best  course  is  to  give  him  a  decided  cathartic,  a 
quart  of  raw  linseed  oil  for  example,  thirty-six  hours  before 
hitching,  and  then  at  first,  work  him  very  moderately  for  several 
hours  as  quick  or  violent  exercise  seems  more  likely  to  bring  on 
an  attack. 

Treatment. — At  the  first  warning  of  azoturia  stop  working 
the  horse  immediately.  Treatment  should  be  done  by  competent 
veterinarians  whenever  such  are  accessible,  for  treatment  is 
difficult. 

The  principal  purpose  of  this  lesson  is  to  direct  attention  to 
prevention  and  not  toward  treatment;  but  cases  will  arise,  and 
these  cases  will  occur  in  sections  where  competent  veterinarians 
are  not  located. 

If  not  voided  naturally,  means  should  be  taken  to  draw  the 
urine  as  soon  as  possible  after  the  disease  appears,  and  three 
times  daily  thereafter.  This  may  frequently  be  accomplished  by 
inserting  a  hand  in  the  rectum  and  pressing  down  moderately 
on  the  bladder.  The  azoturia  patient  has  a  much  better  chance 
for  recovery  if  he  can  be  kept  upon  his  feet  a  portion  of  the 
time  at  least,  and  it  is  very  desirable  that  this  be  done  for 
several  reasons ;  but  slings  should  not  be  used  unless  the  patient 
can  support  a  portion  of  his  weight  upon  the  limbs.  When 
the  patient  is  unable  to  do  this,  put  him  in  a  clean,  dry  stall 
with  plenty  of  bedding  and  turn  him  every  four  hours,  until  he 
can  stand  with  the  aid  of  a  sling.  Quiet  and  rest  are  very 
important. 

Many  different  lines  of  treatment  have  been  used  by  veteri- 
narians during  recent  years,  with  differing  and  even  conflicting 
opinions  as  to  results.  Common  baking  soda  has  been  used  in 
large,  half  pound,  doses.  Some  veterinarians  with  wide  experi- 
ence believe  they  get  best  results  with  good  nursing  and  very 
little  medical  treatment. 

For  a  cathartic,  give  one  quart  of  raw  linseed  oil,  or,  better, 
one  ounce  of  aloes  with  two  drams  ginger,  made  into  a  pill  by 
mixing  these  with  a  little  molasses.  Encourage  the  horse  to 
drink  as  much  as  possible.  If  he  will  not  drink  freely,  he  may 
be  drenched  with  weak  salt  brine  to  make  him  thirsty.     The 


AZOTURIA  221 

more  he  drinks  within  reasonable  limits  the  better.  If  restless 
and  violent,  he  should  have  a  sedative ;  e.g.  1  ounce  broraid  of 
potassium  witli  3  drams  fluid  extract  of  gelsemium,  given  in  half 
a  pint  of  sirup.  If  weather  and  stable  conditions  are  favorable, 
the  muscles  of  his  hips  and  loins  should  be  fomented  with  hot 
water  twice  daily,  two  hours  each  time  during  the  first  few  days 
of  illness ;  after  this  treatment  a  stimulating  liniment  should  be 
used  over  the  muscles  twice  daily  until  the  patient  has  recovered. 

"When  chronic  paralysis  remains  after  the  acute  stage  has 
passed,  nux  vomica  should  be  used.  Give  one  to  two  drams 
fluid  extract  nux  vomica  or  one  to  three  grains  strychnin  sul- 
phate twice  daily  in  feed.  Begin  with  small  doses  and  gradually 
increase  until  there  appear  symptoms  of  nervousness  and  mus- 
cular twitching;  then  discontinue  or  rapidly  reduce  the  dose. 

Prognosis. — Estimates  of  results  must  be  made  with  great 
caution,  for  sudden  and  unexpected  changes  occur,  A  large 
percentage  of  azoturia  cases  die  in  general  practice.  Prognosis  is 
bad  when  complete  paralysis  occurs;  when  the  disease  develops 
violently  from  the  start,  the  horse  going  down  at  the  beginning 
and  soon  losing  control  of  both  limbs ;  or  when  the  patient  grows 
more  and  more  restless  during  the  progress  of  the  disease,  and 
is  unable  to  support  part  of  his  weight  in  the  sling.  It  is  a 
hopeful  sign  if  the  patient  can  stand  alone,  or  fairly  well  when 
assisted  by  sling. 


LECTURE  XLV 
LYMPHANGITIS  (ELEPHANT  LEG) 

In  general,  lymphangitis  is  an  inflammation  of  any  lymphatic 
tissues,  but  in  veterinary  practice  it  usually  refers  to  those  of 
the  hind  leg  of  the  horse.  It  appears  suddenly  and  is  quite 
painful,  although  rarely  fatal. 

Cause  and  history. — This  disease  usually  appears  among 
heav;y'  horses  of  sluggish  temperament,  such  horses  seeming  much 
more  susceptible  than  others,  and  it  almost  invariably  occurs 
among  those  that  are  full  fed  and  have  had  a  period  of  idleness, 
perhaps  of  only  one  day.  In  some  cases,  it  results  from  a  local 
infection,  in  the  foot,  for  example. 

Symptoms. — This  disease  usually  makes  its  appearance  with 
a  chill,  followed  by  fever.  The  horse  is  uneasy  and  in  evident 
discomfort.  A  sudden  extensive  swelling  appears  on  the  upper 
inside  portion  of  the  hind  limb.  The  swelling  increases  grad- 
ually, extending  around  the  limb  and  downward.  The  lymph 
vessels  are  swollen  and  corded.  Lymph  glands  high  up  in  the 
inguinal  region  or  groin  become  involved ;  and  these  may  even 
develop  abscesses,  but  this  is  rare.  Actual  death  of  the  patient 
from  septic  infection  may  even  occur. 

The  horse  is  quite  lame,  and  the  affected  limb  is  very  sensitive 
to  the  touch.  He  perspires  freely ;  the  pulse  is  increased ;  res- 
piration is  somewhat  hurried  and  the  temperature  is  raised. 
The  bowels  are  constipated  and  the  urine  is  usually  dark, 
colored,  and  scanty. 

Most  of  the  swelling  in  the  limb  gradually  subsides,  and  as 
this  general  swelling  goes  down,  the  inflamed  lymph  vessels 
ajipear  as  long,  cordy  swellings.  Usuallj'  some  thickening  and 
enlargement  of  the  leg  remains  and  this  disease  is  apt  to  recur, 
each  time  leaving  a  somewhat  increased  enlargement  until  finally 
there  develops  what  is  commonly  known  as  elephant  leg. 

Lymphangitis  might  be  confused  with  simple  dropsy  or  with 
glanders.  It  can  be  distinguished  from  simple  dropsy,  however, 
by  its  acute  pain,  its  fever,  lameness,  and  cordy  swellings ;  and 

222 


LYMPHANGITIS   (ELEPHANT  LEG)  223 

it  may  be  distinguished  from  the  farcy  form  of  glanders  by  its 
more  acute  fever  and  more  acute  local  trouble  in  the  leg;  by 
its  early  inflammation  of  lymph  glands  in  the  groin,  its  absence 
of  farcy  buds,  and  failure  to  react  to  mallein  test. 

Prevention. — The  grain  ration  should  be  very  greatly  reduced 
during  idle  periods.  This  is  true  for  any  horse  in  fairly  good 
tlesh,  and  particularly  true  of  horses  of  the  type  that  has  been 
mentioned  as  especially  subject  to  lymphangitis. 

Treatment. — Prompt  and  vigorous  treatment  seems  to  abort 
the  disease  in  a  fair  proportion  of  cases.  Hot  fomentations  over 
the  swollen  part,  continued  for  several  hours,  are  one  of  the  most 
important  parts  of  the  treatment.  Bet^Yeen  the  periods  of  fo- 
mentation there  should  be  given  a  vigorous  friction — rubbing 
upward — and  long-continued  light  exercise.  If  the  horse  is 
able  to  walk,  he  should  be  kept  moving  about  slowly  for  several 
hours  at  a  time.  During  the  first  3  or  -4  days,  and  until  the 
active  symptoms  abate  and  the  horse  is  again  receiving  normal 
exercise,  the  food  should  be  light  and  laxative.  Later  full  feed 
may  be  resumed. 

For  acute  cases  with  high  fever,  four  or  five  quarts  of  blood 
may  be  drawn  from  the  jugular  vein.  A  moderate  physic  should 
be  given :  e.g.,  4  to  8  drams  of  aloes  in  a  physic  ball ;  or,  14 
pound  Epsom  salts  dissolved  in  a  pint  or  more  of  water,  3  times 
a  day  may  be  substituted  for  the  aloes.  One-ounce  doses  of 
acetate  of  potash,  dissolved  in  two  pints  of  water  and  used  as  a 
drench,*  or  given  in  the  drinking  water — if  the  horse  will  take 
it  so — should  be  given  three  times  daily  for  a  day  or  two. 

Prognosis. — Lymphangitis  usually  ends  in  recovery  so  far 
as  the  general  disturbances  are  concerned.  Something  may  be 
estimated  concerning  the  i)robable  severity  and  duration  of  ill- 
ness by  noting  the  severity  of  the  chill  which  comes  at  the  begin- 
ning of  the  attack. 


LECTURE  XLVI 
LAMINITIS  (FOUNDER) 

Laminitis  is  a  painful  and  rather  frequent  disease  most  com- 
mon in  horses  but  other  classes  of  stock  are  subject  to  it. 
It  is  commonly  called  founder  and  is  essentially  an  inflamma- 
tion of  the  sensitive  parts  within  the  hoof,  especially  the  sensi- 
tive lamina?.  Founder  is  more  common  in  the  front  feet,  but 
may  affect  either  or  both  the  front  and  hind  feet. 

Symptoms. — The  horse  shows  unmistakable  evidence  of  ex- 
treme pain  and  usually  persists  in  lying  down.  The  pain  is 
due  to  the  fact  that  the  horny  wall  and  sole  do  not  permit  the 
inflamed  tissues  to  expand.  Respiration,  pulse,  and  tempera- 
ture may  increase  as  a  direct  result  of  the  pain ;  the  fever  may 
be  marked,  the  pulse  full  and  strong,  and  the  attitude  and 
expression  indicating  anxiety.  If  the  front  feet  are  affected, 
the  horse  carries  as  much  of  the  weight  as  possible  upon  the 
hind  feet,  the  two  front  limbs  extending  forward.  If  the  hind 
feet  are  involved,  he  extends  them  forward  and  stands  with  the 
front  feet  back,  under  the  body,  and  carrying  as  much  weight 
as  possible  to  relieve  the  sensitive  hind  feet  from  pressure.  He 
refuses  to  back,  and  the  artery  (planter)  just  above  the  ankle 
throbs.  There  is  often  excessive  perspiration  and  a  tendency  to 
constipation  unless  the  case  be  associated  with  excessive 
diarrhea. 

Causes. — Laminitis  frequently  results  from  disturbances  of 
the  digestive  organs,  due  to  unusual  over-feeding,  for  example, 
or  to  a  large  quantity  of  cold  water,  drunk  when  a  horse  is  very 
hot  or  tired.  It  may  be  caused  by  unaccustomed  concussion  on 
hard  roads,  in  case  of  a  horse  not  accustomed  to  this  work,  or 
by  exhaustion,  and  exposure  to  cold  wind  or  cold  water.  Lami- 
nitis often  occurs  in  one  front  foot,  or  one  hind  foot,  as  an  indi- 
rect result  of  lameness  in  the  opposite  limb ;  the  horse  overworks 
the  sound  limb  in  order  to  relieve  pain  in  the  lame  one,  and 
thus  causes  laminitis  in  the  foot  which  had  been  sound.  Lami- 
nitis is  frequently  associated  with  parturition  (delivery)  in  the 

224 


LAMLNITIS   (FOUNDER)  225 

mare  or  cow,  or  with  pneumonia,  or  bronchitis.  Laminitis  espe- 
cially is  apt  to  occur  in  a  horse  that  is  worked  during  a  period 
of  digestive  disturbance. 

Pathology. — There  is  first  of  all  an  inflammation  of  the  sensi- 
tive parts  within  the  hoof,  especially  tlie  sensitive  laminte,  and 
velvety  tissue.  In  severe  cases,  this  inflammation  may  become 
supi)urative.  This  early  inflammation  is  followed  by  an  exu- 
date, which  may  be  either  slight  or  profuse  and  more  or  less 
persistent.  In  persistent  eases  with  considerable  exudate,  the 
toe  of  the  os  pedis  (third 
phalanx)  is  gradually 
drawn  dowuAvard  against 
the  sole,  leaving  the  sole 
convex,  and  the  horse  per- 
manently unsound. 

Termination.    —    Lami- 
nitis may  terminate  in  re- 
covery  and  practical   res- 
toration    of     the     affected      fig.  76.— Foundered  Hoof,     (B.  A.  I.) 
parts,  or  there  may  remain  Au  old  case. 

a  convex  sole  and  a  chronic 

soreness  with  a  tendency  for  the  hoof  to  grow  to  an  unnatural 
shape.  See  Figiire  76.  In  the  latter  case,  the  wall  becomes 
wrinkled  transversely,  and  grows  unevenly. 

Treatment. — These  are  usually  serious  cases,  and  call  for  pro- 
fessional attendance  and  skill  if  such  is  obtainable.  Any  general 
treatment  that  could  be  suggested  might  be  unwise  in  some 
cases,  and  wrongly  applied  in  others. 

A  treatment  that  is  frequently  satisfactory  consists  in  keep- 
ing the  feet  wrapped  with  burlap  and  wet  with  cold  water  for 
some  time — several  days  if  necessary.  Sometimes  this  may  be 
done  by  standing  the  horse  in  a  shallow  stream,  preferably  with 
a  soft  bottom,  or  a  pack  of  crushed  ice  maj^  be  used. 

If  he  is  compelled  to  stand  for  any  great  length  of  time  in 
order  to  keep  the  feet  in  cold  water,  then  he  should  be  sup- 
ported by  a  sling.  AYhen  a  horse  must  be  kept  in  the  stable,  he 
should  have  a  large  box  stall  with  deep,  soft  bedding.  Severe 
cathartics  must  be  avoided,  but  it  may  be  desirable  to  give  very 
mild  doses  of  aloes,  or  raw  linseed  oil.  A  dose  of  aloes  for  this 
purpose  would  be  one  half  ounce  or  less;  that  of  the  oil  would 
be  about  one  pint,  either  one  repeated  as  necessary.     Two  to 


226  VETERINARY  STUDIES 

three  or  even  four,  ounces  of  saltpeter  also  may  be  given,  dis- 
solved in  drinking  water,  or  as  a  drench  in  a  pint  of  water,  three 
times  daily.  Large  doses  of  alum  often  give  especially  good 
results,  particularly  in  cases  where  the  foot  trouble  follows  a 
digestive  disturbance.  The  alum  is  administered  in  2-ounce 
doses  every  two  hours,  each  dose  dissolved  in  one  quart  of  water 
and  continued  if  necessary  until  a  limit  of  six  or  eight  doses 
have  been  given.    During  this  treatment  little  water  is  allowed. 

Ordinarily  the  shoes  should  be  removed  and  the  toe,  if  long, 
shortened ;  but  the  sole  should  not  be  thinned  or  otherwise  inter- 
fered with.  If  the  horse  is  compelled  to  stand  he  may  do  so 
more  comfortably  with  shoes  that  are  rounded,  high  in  the 
center  and  thin  at  toe  and  heels.  If  the  pain  is  extreme,  and 
not  eased  by  soft  bedding  and  continuous  application  of  cold 
water,  then  som.ething  should  be  given  to  relieve  it.  If  an  acute 
case  can  be  induced  to  lie  down,  great  relief  and  rapid  improve- 
ment in  respiration,  pulse,  and  pain  are  soon  noted. 

Prevention. — Intelligent  care  will  prevent  many  ordinary 
cases  of  laminitis.  Accustom  horses  to  markedly  changed  con- 
ditions gradually.  This  applies  especially  in  case  of  fat  and 
idle  horses  put  to  work  and  to  country  horses  put  on  city  pave- 
ment. Keep  a  heated  horse  out  of  cold  winds  and  cold  water. 
Avoid  overfeeding  and  overdriving,  and  feed  a  hot  horse  or 
tired  horse  very  cautiously. 


LECTURE  XLVII 
HEAVES 

This  is  a  disease  of  horses.  It  is  characterized  by  a  peculiar 
disturbance  of  respiration,  in  which  althoujjjh  inspiration  is 
about  normal,  there  is  difficult  expiration,  the  air  being  expelled 
by  two  distinct  movements  instead  of  the  normal  one. 

True  heaves  is  usually  associated  with  the  feeding  of  consid- 
erable quantities  of  timothy  and  clover  hay — especially  dusty 
hay — and  it  lessens  very  materially  the  value  and  usefulness 
of  horses  affected  by  it.  Light  feeders  are  as  a  rule  free  from 
this  disorder,  while  horses  that  eat  hay  greedily  are  most 
liable  to  have  it. 

In  the  lungs  of  horses  so  affected,  the  air  vesicles  are  gradually 
dilated,  losing  their  elasticity;  they  may  even  rupture  together 
so  as  to  produce  small  cavities,  from  which  the  air  is  expelled 
with  great  difficulty.  During  forced  expiration,  the  air  may 
escape  into  the  surrounding  tissue.  This  escape  of  air  from  the 
air  cells  into  the  lung  tissues  (emphysema)  usually  occurs  in 
connection  with  heaves,  but  its  relation  to  the  disease  is  quite 
problematical.  Plainly  a  horse  may  have  such  air  leakage  with- 
out heaves.  This  condition  is  probably  to  be  regarded  as  an 
effect  rather  than  a  cause. 

Cause. — Any  chronic  irritation  of  the  bronchial  mucous  mem- 
brane may  cause  heaves — chronic  bronchitis  and  severe  cough, 
for  example,  or  repeated  violent  exercise  by  a  horse  not  in 
condition.  But  we  may  say  that  the  usual  direct  cause  of 
heaves  is  the  excessive  eating  of  bulky  food,  especially  hay  that 
is  overripe  and  dusty,— or  worse,  musty.  Tame  hay  cut  very 
ripe  and  dusty  clover  hay  are  both  prone  to  cause  tliis  trouble, 
which  rarely,  if  ever,  develops  in  horses  on  pasture  or  that 
have  only  bright,  wild  hay  or  a  reasonable  (|uantity  of  early-cut 
tame  hay.  This  disease  is  said  to  be  almost  unknown  in  arid 
regions  where  timothy  and  clover  hay  are  grown  by  irrigation, 
and  where  such  hay  is  never  exposed  to  dew  or  rain  and  there- 
fore does  not  develop  fungi  to  a  serious  extent.    Mere  bulk  and 

227 


228  VETERINARY  STUDIES 

over-ripeness  are  probably  not  the  only  factors.  Many  eases  of 
heaves  may  be  due  to  fungi,  especially  their  spores,  rather  than 
to  the  character  of  the  food  with  which  the  fungi  are  taken. 

Symptoms. — A  peculiar,  explosive  cough  usually  appears  be- 
fore the  breathing  becomes  noticeably  disturbed.  After  a  time 
it  is  noticed  that  exercise  produces  unusual  difficulty  in  breath- 
ing, the  air  being  taken  in  quite  easily  but  expelled  with  dif- 
ficulty. When  this  stage  develops,  the  air  is  expelled  in  two 
efforts  instead  of  one,  the  latter  portion  of  the  tidal  air  being 
expelled  by  a  special  effort  of  the  belly  muscles.  Overfeeding, 
of  course,  increases  the  difficulty. 

Some  cases  of  heaves  may  be  disguised  temporarily  by  the 
use  of  drugs  and  the  feeding  of  a  concentrated  diet.  This  trick 
may  usually  be  detected,  however,  by  allowing  the  horse  a 
hearty  feed  and  water,  and  then  giving  active  exercise  or  even 
by  actively  exercising  him  without  the  special  feeding  and  water- 
ing. A  horse  drugged  with  any  belladonna  preparation  shows 
greatly  enlarged  pupils  of  the  eyes.  It  is  usually  easy  to  dis- 
tinguish between  heaves  and  roaring.  The  latter  is  a  disease 
of  the  larynx  due  to  paralysis  of  one  of  the  laryngeal  carti- 
lages and  is  shown  by  the  abnormal  sounds  known  as  roaring 
or  whistling  during  inspiration,  the  movements  of  the  flank  and 
chest   being   normal. 

Prevention. — The  prevention  of  most  cases  of  heaves  may  be 
easily  described  and  almost  as  easily  accomplished — by  mere 
avoidance  of  well-known  causes.  There  is  a  very  general  and 
wasteful  feeding  of  hay.  This  is  not  merely  a  waste;  it  is  an 
injury  to  the  horse.  A  case  of  heaves  due  to  over-feeding  is 
usually  discredit  to  the  feeder.  Heaves  often  indicates  that 
the  horse  is  a  good  feeder  and  under  wiser  management  would 
be  able  to  digest  a  large  amount  of  food  and  do  hard  work. 
There  is  no  satisfactory  evidence  that  heaves  is  hereditary,  and 
no  proof  to  the  contrary. 

It  is  not  wise  to  allow  a  horse  to  do  very  fast  or  hard  work 
on  a  distended  stomach,  which  means  that  the  work  should  be 
slower  and  easier  during  the  first  hour  or  so  after  hearty  meals. 
Little  hay  should  be  fed  in  the  morning,  and  at  noon,  and  a 
reasonable  quantity  in  the  evening. 

To  prevent  heaves,  then,  feed  reasonable  quantities  of  good 
wild  hay,  or  tame  hay  cut  early  and  not  allowed  to  become 
musty.     Avoid  dusty   foods.     The   amount  of  hay   should  be 


HEAVES  229 

restricted  to  much  less  than  is  usually  fed.  Horses  that  are 
greedy  feeders  should  be  bedded  with  sawdust  or  shavings  or 
protected  by  a  muzzle  in  case  other  bedding  is  used. 

Autopsy. — On  examination  post  mortem,  the  lungs  may  be 
found  to  be  somewhat  bloated  and  to  contain  more  air  than 
normal.  The  chambers  in  the  right  side  of  the  heart  are  apt  to 
be  enlarged  and  their  walls  tliickened.  In  examining  the  lungs 
of  long-standing  cases  of  heaves,  we  note  that  they  are  pale  and 
tloat  abnormally  high  in  water,  due  to  the  emphysema  or  air 
in  the  tissues  previously  mentioned.  The  stomach  is  often  larger 
than  normal,  due  to  the  overeating  of  bulky  foods  and  conse- 
quent stretching. 

Treatment. — In  cases  of  heaves  avoid  overripe  and  dusty  hay. 
Allow  little  bulky  food  of  any  kind.  Give  a  small  quantity  of 
hay  for  the  morning  feed,  none  at  noon,  and  a  very  moderate 
amount  in  the  evening — much  less  than  would  be  considered  care- 
ful feeding  for  a  healthy  horse.  If  the  hay  or  grain  is  dusty, 
sprinkle  it  as  a  regular  custom.  Use  such  horses  for  slow  work, 
and  give  as  much  rest  as  possible  after  meals. 

A  month  or  two  of  this  management  will  very  greatly  improve 
most  cases. 

]\Iedical  treatment  is  considered  unsatisfactory  so  far  as  cura- 
tive effect  in  bad  cases  is  concerned.  Fowler's  solution  in  one- 
ounce  doses  three  times  a  day  in  the  feed,  long  continued  and 
coupled  with  careful  feeding,  is  often  a  great  help.  Proper 
feeding  alone  may  be  said  to  be  almost  curative,  although  sub- 
sequent attacks  are  easily  brought  on  by  injudicious  manage- 
ment. 


LECTURE  XLVIII 
HOVEN,  OR  BLOAT  (ACUTE  TYMPANITES) 

Hoven,  or  bloat,  is  a  form  of  indigestion  in  cattle  and  sheep 
which  is  characterized  by  an  abnormal  collection  of  gas  in  the 
first  stomach  or  paunch. 

Causes. — Bloat  is  caused  by  excessive  fermentation,  which 
results  indirectly  from  such  conditions  as  sudden  changes  from 
dry  food  to  pasture,  or  from  one  pasture  to  a  better  one,  or 


Fig.  77. — Showing  Where  to  Tap.     (M.  H.  E.) 
See  white  cross  in  the  flank. 


from  grass  to  clover.  Easily  fermented  foods  favor  lioven. 
Grasses  or  clovers,  wet  by  dew  or  rain,  seem  especially  apt  to 
cause  hoven. 

Frosted  roots  and  impaction  from  overfeeding  may  also  re- 
sult in  arrested  digestion,  and  then  hoven  ensues.  Sick  cattle 
frequently  bloat  after  lying  for  a  long  time  on  the  side.  Choke 
often  leads  to  hoven. 

230 


HOVEN,  OR  BLOAT   (ACUTE  TYMPANITES)       231 

Symptoms. — There  is  extreme  distention  of  the  stomach,  most 
prominent  on  the  left  side  with  consequent  difficulty  in  breath- 
ing:. The  pulse  may  be  nearly  imperceptible.  The  animal 
moans,  may  stagger  and  fall,  then  die  in  convulsions. 

Treatment. — If  breathing  is  difficult,  do  not  wait  for  the  ef- 
fect of  medicines ;  sheep  require  very  prompt  treatment  to  save 
them.  Tap  with  trocar  and  cannula,  high  in  the  left  flank  and 
well  forward.  (See  Fig.  77.)  The  tube  (cannula)  may  be  left 
in  the  flank  for  some  time  if  gas  continues  to  accumulate. 

Then  give  the  following  as  one  dose  in  one  pint  of  sirup: — 

(A)      Arinnalic  sjiirils  of  ainiiioiiiu 2  oz. 

Tuiiioiitiiie    2  oz. 

This  is  a  suitable  dose  for  a  thousand  pounds  live  weight. 
Repeat  this  in  half  an  hour  if  necessary  or  give  one  double  dose ; 
or  give  (B)  4  oz.  hyposulphite  of  soda  in  6  ounces  water 
every  half  hour  until  gas  ceases  to  accumulate  or  until  a  limit 


Fig.   78. — Trocar  and  Cannxtla. 
For  tapping  bloated  sheep  and  cattle. 


of  six  doses  have  been  given.  A  third  method  consists  of  alter- 
nating the  two  doses  (A  and  B)  just  described  at  half  hour 
intervals. 

Half  an  ounce  of  formalin  in  a  cpiart  of  water  is  a  very  effec- 
tive remedy.  For  mild  cases,  a  large  hay  rope  placed  in  the 
mouth  and  tied  around  the  liead  is  useful.  Vigorous  massage 
of  the  l)elly  by  two  men  witli  a  limber  pole  is  useful  in  such 
cases.  Both  of  the  latter  methods  are  more  effective  when  sheep 
are  made  to  stand  high  in  front,  or  on  their  hind  legs  or  when 
cattle  are  made  to  stand  with  the  front  i)arts  high  as  possible. 

Do  not  exercise  a  badly  bloated  cow  or  sheep.  To  do  .so  is 
dangerous,  because  the  breathing  is  interfered  with  by  the  pres- 
sure of  the  stomach  against  the  diai)liragm.  When  the  acute 
symptoms  have  subsided  give  the  following  for  physic: 


232  VETERINARY  STUDIES 

Epsom  salts   1  lb. 

Glauber  salts Va 

Ginger  (gTOund)    3  oz, 

F.  e.  nux  vomica 3  drams 

Dissolve  these  in  three  pints  hot  water  and  use  the  solution 
as  a  drench;  repeat  in  16  hours  if  bowels  do  not  move  freely. 

Prognosis. — A  large  percentage  of  cases  recover  if  properly 
treated  soon  after  disease  appears.  Death  occurs  from  asphyxia, 
rupture  of  the  paunch,  or  rupture  of  the  diaphragm. 

Prevention.— H oven  is  likely  to  be  quickly  fatal  to  sheep; 
hence,  sheep  should  be  closely  watched,  when  they  are  first  put 
on  dangerous  feed  like  green  clover,  rape  or  alfalfa.  A  large 
proportion  of  these  cases  may  be  prevented,  but  some  will  ap- 
pear occasionally  under  conditions  which  cannot  be  prevented. 
There  are  two  reasonably  safe  methods  of  turning  cattle  and 
sheep  on  new  pasture  at  any  season;  from  a  poor  to  a  richer 
pasture;  or  from  grass  to  clover.  First,  feed  heavily  and  then 
turn  them  on  the  new  pasture  for  a  few  minutes  the  first  day, 
and  increase  this  time  a  little  each  day  for  a  week.  Or  second, 
give  the  cattle  or  sheep  a  large  ration  of  the  dry  food  to  which 
they  have  been  accustomed,  for  several  days  before  they  are  to 
be  turned  on  the  new  feed;  feed  later  than  usual  on  the  last 
morning  and  then  turn  them  out  as  soon  as  they  are  done  eat- 
ing, which  should  be  after  the  dew  is  off  the  grass  and  not  soon 
after  a  rain.  Under  these  conditions,  cattle  and  sheep  usually 
may  be  turned  on  grass  in  the  spring  or  put  on  new  or  dif- 
ferent pasture  and  left  there  with  little  risk. 

Pastures  where  the  old  grass  stands  quite  heavy,  and  the 
young  grass  has  grown  up  in  it,  are  much  less  dangerous  than 
those  where  the  stock  gets  only  the  new  grass.  When  cattle  or 
sheep  are  once  safely  on  a  rank  pasture,  or  clover,  alfalfa,  etc., 
the  more  continuously  they  can  be  left  there,  the  safer  they  are. 


LECTURE  XLTX 

PARTURIENT  PARALYSIS  (MILK  FEVER) 

This  serious  disease  of  eows  usually  appears  within  a  very- 
few  days  after  calving;,  althougfh  it  may  appear  before  or  some 
time  after  calving.  Its  cause,  nature,  and  pathology  are  not 
well  understood.  However,  prevention  and  treatment  are,  as  a 
rule,  very  satisfactory. 


Fig.  79. — Partitrient  Paralysis — ^Milk  Fever.     {M.  H.  R.) 
Early  stage.     Unsteady  on  hind  legs. 


Causes. — The  causes  of  parturient  paralysis  are  of  two  classes, 
predisposing  and  precipitating. 

Predisposing  causes  include  age  (maturity),  heavy  feeding 
and  milking  qualities,  pregnancy,  easy  delivery,  lack  of  exer- 
cise, and  high  temperature  in  stables.  The  cow  that  is  a  heavy 
feeder  and  milker  and  in  the  prime  of  life,  with  her  third  or 

233 


234 


VETERINARY  STUDIES 


fourth  calf,  is  the  one  most  subject  to  this  disease.  A  young 
heifer,  an  old  cow,  or  a  cow  in  thin  flesh  and  underfed  during 
pregnancy,  is  not  likely  to  have  this  disease. 

Precipitating  causes  include  delivery,  sudden  increase  of  gland 
activity  in  the  udder,  disturbance  of  circulation,  anxiety  and 
exposure  to  cold  and  damp. 

Symptoms. — These  are  known  as:  early  or  warning,  and 
diagnostic,  or  positive. 


mmm  -amm. 


^im^ 


<-^*5»- 


Fig.  80. — Partukient  Paralysis.     (M.  H.  E.) 
Later  stage.     Head  held  unsteadily. 

Early  symptoms. — Uneasiness,  sudden  constipation,  eyes  either 
stupid  or  wild,  tail  switching  uneasily,  and  checked  milk  flow 
are  early  symptoms  of  milk  fever.  The  gait  is  peculiar,  show- 
ing imperfect  control  of  the  posterior  limbs.  Such  symptoms,  if 
occurring  during  the  first  five  days  after  calving,  or  within  two 
days  before  should  warn  of  danger. 

Diagnostic  symptoms.— The  patient  goes  down,  is  more  or  less 
unconscious  and  lies  in  a  peculiar  position,  with  her  head  in  the 
flank;  she  loses  sensation  and  power  of  voluntary  motion,  the 
sensory  and  motor  nerves  become  paralyzed;  her  pupils  dilate; 
she  is  unable  to  swallow;  her  pulse,  at  first  bounding  and  full, 
is  later  depressed;  her  temperature  is  usually  normal,  or  even 
sub-normal;  respirations  are  slow.     In  typical  cases,  the  symp- 


PARTURIENT  PARALYSIS   (MILK  FEVER)         235 

toms  are  uniform  and  plain;  but  some  atypical  eases  are  not 
easily  recoguizocl. 

Prevention. — Prevention  is  always  more  satisfactory  than 
treatment.  P'or  a  heavy  milker,  sudden  changes  in  diet  are  to 
be  avoided,  unless  toward  one  lighter  and  more  laxative  just 
before  calving.  It  is  sometimes  advisable  to  change  especially 
susceptible  cows  from  pasture  to  light,  dry  feed.  Food  should 
be  light,  laxative,  easily  digested,  and  small  or  moderate  in 
quantity.    Exercise  is  desirable.    A  mild  laxative  may  be  given 


.ur^X.^f^=3^r 


Fig.  81. — Parturient  Paralysis. 

Cow  very  stupid.    Skin  has  lost  sensation.    Head  in  the  flank.   Still  later 
stage. 


2  to  5  days  before  calving,  one  quart  raw  linseed  oil,  for  ex- 
ample. 

Allow  the  cow  abundant  exercise  during  the  last  month  of 
pregnancy,  and,  if  she  is  nervous,  leave  the  calf  near  hei-  for  a 
few  days. 

Usually  there  should  be  no  milk  drawn  before  calving  and  but 
little  removed  during  the  fii'st  twenty-four  hours  afterward, 
not  more  than  the  calf  would  take  naturally.  This  precau- 
tion is  especially  important  as  a  preventive  of  milk  fever  in 
high-type  dairy  cows,  and  is  reasonably  satisfactory  if  followed 
with  intelligence. 

Treatment. — Acute  cases  are  liable  to  die  in  12  to  24  hours  if 
not  treated  ;  others  may  improve  greatly  and  then  relapse.  Since 
these  cases  require  skilful  treatment,  and  the  affected  animals 
are  usually  valuable,  stockmen  sliould  not  treat  them  if  com- 
petent veterinary  services  may  be  had.     A  line  of  treatment  is 


236  VETERINARY  STUDIES 

suggested  here  because  cases  for  the  stockman  however  fre- 
quently occur  where  it  is  not  possible  to  obtain  professional 
assistance. 

The  patient  must  not  be  allowed  to  lie  flat  on  the  side  on 
account  of  danger  from  hoven,  but  should  be  propped  up  by 
means  of  bags  of  sand,  bran,  or  hay,  so  that  she  lies  on  the 
sternum.  If  the  head  is  thrown  around  violently,  it  should  be 
supported  by  means  of  a  rope  tied  to  some  overhead  support. 
The  cow  must  also  be  kept  quiet  and  thoroughly  warm  and  dry. 
Severe  cases  may  require  stimulants,  like  strychnin  or  camphor 
oil  (1:4)  hypodermically  injected.  Retain  heat  in  cold  weather 
by  a  covering  of  four  or  five  blankets.  Draw  urine  twice  daily 
and  use  large  quantities  of  slightly  irritating  rectal  injections 
repeated  several  times,  if  necessary.  Give  no  medicine  or  liquid 
food  by  the  mouth,  except  as  directed  by  a  competent  veteri- 
narian, bcause  of  difficult  swallowing  and  the  danger  of  pro- 
ducing fatal  pneumonia  in  a  case  that  should  have  recovered. 

Air  treatment. — The  injection  treatment  for  milk  fever  has 
passed  gradually  through  several  stages  from  iodid  of  potash 
solution  (Schmidt  treatment)  to  various  other  solutions,  then 
to  oxygen  gas,  and  finally  to  simple,  clean  air.  This  air-injection 
treatment  is  the  one  now  in  most  common  use.  Apparently  full 
distention  of  the  udder  is  the  essential  thing,  and  it  matters 
little  what  is  used  for  the  purpose  providing  it  be  clean  and  not 
irritating.  Great  care  in  cleanliness  is  necessary  to  avoid  in- 
fection of  the  interior  of  teat  and  udder  with  germs  which  might 
cause  garget  or  septicemia  (blood  poisoning). 

The  udder  and  teats  should  be  well  brushed,  then  placed  on  a 
clean  towel  or  piece  of  oilcloth  and  disinfected  with  1  to  1000 
corrosive  sublimate  in  water,  or  3  per  cent  lysol  or  creolin,  or  5 
per  cent  carbolic  acid.  The  hands  of  the  operator,  the  teat  tube, 
the  rubber  tubing,  etc.,  should  all  be  disinfected,  the  two  latter 
by  boiling.  After  the  teat  tube  is  disinfected,  it  should  not  be 
carelessly  handled  or  be  allowed  in  contact  with  anything  that 
can  contaminate  it.  Bacterial  cleanliness  is  of  the  utmost  im- 
portance. Air  is  injected  by  a  special  syringe  in  which  it  is 
filtered  through  cotton  before  entering  the  udder.  The  utmost 
care  must  be  taken  as  to  clean  handling  and  the  injection  of 
clean  air.  Tlie  quarters  are  milked  out  and  pumped  full  of  the 
filtered  air;  it  is  well  to  give  the  udder  massage  treatment  in 
order  to  disseminate  the  air  through  the  milk  ducts  during  the 


PARTURIENT  PARALYSIS   (MILK  FEVER)         237 

injection  process.  A  broad  tape  is  tied  around  the  teat  and  left 
on  for  about  six  hours. 

The  injection  may  be  repeated  in  three  to  six  hours  if  neces- 
sary. In  an  emergency,  an  ordinary  bicycle  pump  connected 
by  rubber  tubing  to  a  milk  tube  may  be  used,  but  this,  of  course, 
does  not  filter  the  air. 

Prognosis. — It  is  difficult  to  make  an  accurate  estimate.  But 
there  is  in  general  a  good  prospect  of  recovery  in  serious  look- 
ing cases  if  they  are  properly  and  promptly  treated. 

Sudden  and  unexpected  variations  occur.  Mortality  under 
the  air  treatment  is  not  large.  The  prospect  is  less  favorable  if 
the  ease  develops  soon  after  calving ;  if  it  develops  rapidly 
and  seems  to  overwhelm  the  system ;  if  there  is  decided  loss  of 
animal  heat ;  if  tjTiipanites  or  bloating,  or  convulsion  occurs ; 
if  the  cornea  becomes  insensible ;  if  the  lower  lip  hangs  loosely. 

The  prospect  is  favorable  if :  the  circulation  remains  good ; 
if  feces  are  passed ;  or  the  patient  attempts  to  rise  or  eat ;  if 
rectal  irritation  causes  a  discharge  of  feces,  or  a  subnormal  tem- 
perature changes  to  normal. 


LECTURE  L 
CHOKE 

Choking,  as  ordinarily  understood,  is  an  obstruction  in  any 
portion  of  the  pharynx  or  esophagus.  In  horses  it  is  more  com- 
monly caused  by  diy  food,  rapidly  eaten.  Cases  in  which  a 
long  section  of  the  esophagus  is  packed  with  soft,  dry  food  are 
especially  difficult  to  handle  successfully.  Cows  more  frequently 
choke  on  pieces  of  roots,  pumpkins,  and  even  old  bones. 

Symptoms. — The  horse  or  cow  stops  eating  suddenly  and 
makes  ineffectual  efforts  to  swallow,  then  there  are  spasmodic 
actions  of  the  neck  and  belly  muscles.  When  the  animal  at- 
tempts to  drink,  some  of  the  water  returns  through  the  nose. 
If  the  obstruction  is  of  considerable  size  and  is  located  along 
the  neck  portion  of  the  esophagus,  it  may  usually  be  seen  or  felt. 
There  is  usually  a  profuse  flow  of  saliva,  and  particularly  in 
the  case  of  cattle  an  involuntary  chewing  action.  If  the  chok- 
ing occurs  in  the  thoracic  portion,  then  medicines  or  liquids  are 
swallowed  in  small  quantities  without  difficulty  until  the 
esophagus  is  full,  when  they  return  by  the  mouth,  causing  the 
animal  to  cough.  There  is  usually  marked  dejection  and  dis- 
tress, with  an  appearance  of  anxiety,  food  and  water  are  re- 
fused.    Cattle  frequently  bloat. 

Prevention. — Roots  should  be  sliced  or  pulped  unless  they  are 
large.  Cows  often  choke  when  eating  hurriedly,  especially  when 
attempting  to  swallow  under  threatened  attack  from  some  other 
member  of  the  herd.  Hence  individual  feeding  lessens  this. 
Horses  choking  on  dry  feed  are  almost  invariably  rapid  eaters, 
and  for  such  horses  it  is  well  to  avoid  dry  bran.  Grain,  espe- 
cially oats  or  similar  food,  should  be  fed  in  such  a  way  that  the 
horse  gets  it  slowly;  it  may  be  scattered  over  the  bottom  of  a 
large  manger,  for  instance — any  device  which  forces  the  horse 
to  eat  slowly  lessens  the  difficulty.  It  should  also  be  borne  in 
mind  that  an  animal  which  has  once  choked  is  liable  to  a  stric- 
ture, with  consequent  recurrence  of  the  same  difficulty,  during 
the  first  week  or  two  after  the  accident. 

238 


CHOKE  239 

Treatment. — In  case  of  choke,  food,  drink,  or  medicine  may 
easily  cause  a  fatal  pneumonia,  by  entering  the  lungs  through 
the  pharynx;  hence  the  need  of  great  caution. 

If  the  obstruction  is  within  reach,  it  should  be  removed  by 
the  hand,  the  teeth  being  held  apart  by  some  suitable  device  to 
protect  the  arm.  A  person  with  long  arm  and  slender  hand  can 
frequently  relieve  choking  in  the  pharynx  or  upper  portion  of 
the  gullet,  especially  if  he  has  an  assistant  to  shove  the  obstruc- 
tion upward  toward  the  hand.  A  thin  glove  with  the  ends  of 
the  fingers  cut  off  is  desirable  for  protecting  the  hand. 

Dry  food  that  cannot  be  reached  by  hand  should  be  softened 
by  the  use  of  oily  or  mucilaginous  drinks,  and  then  gradually 
worked  loose  by  external  manipulation.  Frequently  the  ob- 
structing mass  can  be  loosened  at  the  lower  portion,  a  little 
at  a  time,  and  the  loosened  portion  swallowed. 


Fig.  82. — For  Relieving  Choke.     {M.  IT.  E.) 
Made  of  No.   10  or   12  wire. 

If  the  choke  is  along  the  neck,  and  caused  by  dry  feed  like 
oats  or  bran,  then  water  or  raw  linseed  oil  injected  directly  into 
the  dry  mass  with  a  good  hypodermic  syringe  may  soften  and 
dislodge  the  obstruction.  A  case  of  this  kind  may  often  be 
relieved  by  washing  the  feed  out  through  a  double-current 
stomach  tube.  A  single-current  tube  may  be  used  to  siphon  out 
soft  feed.  Loosen  the  upper  portion  of  the  mass  with  the 
fingers,  then  fill  the  tube  with  water,  drop  the  outer  end,  and 
siphon  out.  Repeat  as  many  times  as  necessary.  For  this  pur- 
pose, or  for  use  as  a  probang,  a  small  sized  lawn  hose,  well 
oiled,  does  very  well.  This  method  is  applicable  whether  the 
obstruction  is  in  the  neck  or  within  the  chest.  A  probang  should 
not  be  used  in  cases  where  the  trouble  is  due  to  di*y  food. 

The  simple  device  shown  in  Figure  82  is  very  satisfactory 
for  relieving  choke  due  to  ]neces  of  vegetables.  It  consists  of  a 
piece  of  No.  10  to  12  wiic,  about  12  feet  long,  the  ends  bent 
together  and  twisted  as  shown  in  the  cut,  leaving  a  suitable  loop 
at  the  point  which  was  origiiuilly  the  middle  of  the  wire.  This 
instrument  is  introduced  into  the  gullet.  The  farther  end  passes 
the  obstruction,  which  is  then  included  by  the  loop.    By  pulling 


240  VETERINARY  STUDIES 

on  the  wire  the  obstruction  is  loosened,  moved  upward  a  short 
distance,  or  removed  entirely.  If  the  obstruction  is  merely 
loosened  then  the  process  is  to  be  repeated.  This  has  proven 
fairly  satisfactory  in  the  writer's  experience.  In  all  such  work 
the  nose  should  be  extended,  the  gullet  be  kept  in  as  straight  a 
line  as  possible,  and  the  work  be  done  carefully.  The  tube  or 
wire  loop  should  be  introduced  slowly  and  carefully,  high  up 
and  well  back  in  the  mouth.  If  the  animal  coughs,  the  instru- 
ment should  be  removed  and  another  trial  made,  as  the  cough- 
ing indicates  that  the  instrument  has  entered  the  trachea. 

Tense,  spasmodic  action  of  the  gullet  gripping  the  choke  may 
be  controlled  by  the  use  of  morphin  or  aconite.  AVhips  and 
other  stiff  instruments  must  be  avoided,  as  they  are  apt  to  tear 
the  gullet  just  below  the  pharynx.  Whatever  is  used  must  be 
smooth  and  flexible.  For  at  least  a  week  after  the  removal  of 
the  obstruction,  the  diet  should  consist  of  soft  food. 

There  is  usually  no  reason  for  haste  in  treating  choke.  Some 
cases  will  recover  naturally  if  water  is  kept  before  them  and 
they  are  left  quietly  alone.  However,  in  severe  cases,  and  when 
ordinary  measures  fail,  call  your  veterinarian  before  you  have 
bruised  and  torn  the  esophagus,  making  the  case  hopeless. 


MISCELLANEOUS  DISEASES 

LECTURE  LI 
UNSOUNDNESS 

If  at  any  time  a  horse  has  any  disease  {e.g.  bone  spavin  or 
heaves)  which  actually  makes  him  less  capable  of  his  proper 
work,  or  which  in  its  ordinary  progress  will  diminish  his  natural 
usefulness,  he  is  unsound.  A  blemish,  e.g.  a  barb-wire  sear, 
impairs  appearance  and  sale  value,  but  not  actual  service,  and 
is  not  an  unsoundness. 

Soundness  is  usually  relative,  being;  rarely  if  ever  absolute 
or  perfect.  What  we  mean  in  passing  a  horse  as  sound,  is  that 
he  is  practically  sound. 

To  be  sound,  then,  a  horse  must  have  no  disease  or  other  con- 
dition that  interferes  or  is  likely  to  interfere  with  his  useful- 
ness. For  instance,  a  horse  may  have  a  spavin,  which  both  les- 
sens his  ability  to  work  and  injures  his  selling  value.  The  same 
would  be  true  of  heaves.  A  horse  may  have  a  disease  from  which 
he  will  recover ;  but  at  the  time  of  examination,  he  "will  be 
technically  unsound. 

Unsoundness  may  be  temporary  or  permanent.  Temporary 
unsoundness  may  be  illustrated  by  an  intluenza,  from  which  a 
horse  would  probal)ly  recover,  or  by  a  light  sprain  or  an  ankle 
bruised  from  interfering.  In  the  latter  case  the  question  would 
arise  at  once  as  to  whether  the  interfering  was  due  to  faulty 
conformation  or  to  faulty  shoeing,  for  the  latter  could  be  easily 
remedied.  In  the  former  case  the  condition  would  be  incur- 
able and  serious;  in  the  latter  condition  it  would  be  unim- 
portant. 

Normal  conditions. — It  is  necessary  first  of  all  to  become 
familiar  with  the  usual  and  unusual  normal  conditions  and  ap- 
pearances for  comparison.  For  instance,  the  hocks  may  be 
perfectly  sound,  and  yet  have  peculiar  bony  development.  In 
such  case  it  will  be  found  that  both  hocks  are  alike.  The  knees 
may  have  a  similar  i)e('uliar  development,  and  yet  be  perfectly 
sound. 

241 


242 


VETERINARY  STUDIES 


Common  Unsoundness  and  Blemishes 

Ringbones,  splints,  spavins,  etc.,  are  abnormal  developments 
of  bone  tissue,  the  result  of  an  inflammation  of  the  periosteum. 
These  are  all  recognized  as  forms  of  unsoundness,  and  usually 
cause  lameness.  The  inflammation  of  the  periosteum  may  have 
its  origin  in  bruises  or  other  injuries,  or  it  may  possibly  be  the 


Fig.  8.3. — Eingbones.     (M.  E.  B.) 

1.  Ring-bone  and  sidebone,  with  general  anchylosis. 

2.  Ringbone  and  sidebone,  with  general  anchylosis  and  marked  bony  en- 
largement. 

3.  High  ringbone  with  anchylosis  on  first  and  second  phalanges. 

4.  Low  ringbone  with  sidebone,  and  anchylosis  of  the  second  and  third 
phalanges. 

5.  Ringbone  with  sidebone^  and  unilateral  anchylosis. 

result  of  an  extending  inflammation  from  some  adjoining  tissue, 
but  in  either  case  the  result  is  usually  a  projecting  development 
of  bony  tissue,  i.e.,  an  exostosis.  Hereditary  tendency  is  an- 
other important  item  among  causes. 

Ringbone. — This  is  characterized  by  an  exostosis  on  some  por- 
tion of  the  pastern  bones.  It  may  be  in  front,  behind,  on  either 
side,  or  extending  entirely  around  the  pastern.  It  may  be  lo- 
cated near  the  crown  of  the  hoof  or  very  much  higher.  Some 
ringbones  involve  the  articulation,  and  are  then  called  articular. 


UNSOUNDNESS  243 

These  necessarily  cause  lameness.  Others  affect  the  extremity 
or  the  shaft  of  the  bones  witlioiit  involving  the  articulation. 
Some  are  due  to  injury,  others  are  of  rachitic  origin  (rickets), 
and  due  to  faulty  nutrition  resulting  in  poor  (juality  of  bone. 

Ringbones  are  usually  much  more  serious  forms  of  unsound- 
ness than  splints,  as  they  are  more  apt  to  be  permanent  in  effect, 
and  even  if  the  soreness  be  relieved,  there  is  likely  to  be  a  me- 
chanical lameness  because  of  a  stiffened  joint.  This  unsound- 
ness and  the  lameness  resulting  from  it  are  very  easily  detected 
in  plain  cases. 

Sidebones. — A  sidebone  is  an  abnormal  condition  of  the  lat- 
eral cartilage— most  common  on  the  external  cartilages  of  the 
front  feet — characterized  by  firmness  under  pressure  and  some- 


Fig.  84.— Sidebones.     (M.  H.  B.) 

Due  to  an  inflammation  and  ossification  of  the  lateral  cartilages:  1,  nor- 
mal OS  pedis;  2,  3,  4,  varying  types  of  sidebones. 

times  enlargement.  These  cartilages  are  normally  quite  elastic. 
The  firmness  is  due  primarily  to  a  deposit  of  lime,  a  process  of 
ossification,  i.e.,  bone  formation — in  the  cartilage  structure. 
Sidebones  are  detected  as  bonelike  structures  which  appear  above 
the  crown  of  the  hoof  at  tlie  quarter  and  just  beneath  the  skin 
on  either  side.  They  may  or  may  not  cause  lameness  during 
the  period  of  inflammation  and  hardening.  In  some  cases  the 
lameness  is  persistent.  Otlier  cases  are  very  slow  and  mild  and 
no  lameness  is  noticed. 

Spavin. — Bone  spavin  is  one  of  the  most  serious  forms  of 
unsoundness.  This  is  a  disease  of  the  tarsal  bones  at  the  lower, 
inner,  front  portion  of  the  hock.  There  is  usually  something 
of  an  exostosis,  varying  from  very  small  size,  commonly  called 
by  horsemen  a  "jack,"  to  very  large  size  which  every  one  rec- 
ognizes as  bone  spavin. 

There  is  another  form  of  bone  spavin  in  which  there  is  a 
slight  or  no  external  development.    In  this  form  there  is  disease 


244 


VETERINARY  STUDIES 


of  the  bones  in  the  deeper  parts ;  and  erosions  of  the  articular 
cartilages.  Bone  spavins  have  a  tendency  to  recover  without 
treatment,  although  in  many  cases  the  period  required  for 
natural  recovery  is  very  long,  extending  through  a  period  of 
years.  In  other  cases  recovery  can  never  occur.  Recovery 
when  brought  about  by  natural  or  artificial  conditions  implies 
that  certain  of  the  tarsal  bones  have  united,  a  process  called 
anchylosis,  i.e.,  union.  Inflamed,  sensitive  surfaces  are  then  no 
longer  rubbing  together  as  the  limbs  move. 


Fig.  85.— Spavins.    Two  Types.     (M.  E.  B.) 

I.  Spavin   with   marked   bony   enlargement.     A,   metatarsals;    B,   tarsals 
with  enlargement  and  anchylosis. 

II.  Blind    spavin.      Extensive    ulceration    of    articular    surfaces ;    no    en- 
largement;  no  anchylosis.     2,  os  calcis;  3,  scaphoid  or  large  cuneiform. 


]\Iany  bone  spavins  doubtless  appear  as  the  result  of  slight 
injuries  in  susceptible  subjects,  particularly  those  that  have  a 
strong  hereditary  tendency  to  disease  of  this  kind. 

Symptoms. — These  cases  come  out  very  lame  after  hard  work, 
step  on  the  toe,  and  improve  with  exercise.  They  often  stand 
with  the  foot  resting  in  a  peculiar  way  against  the  other  hind 
foot.  In  motion  they  carry  the  hock  joint  with  as  little  move- 
ment as  possible  and  step  on  the  toe. 

What  is  known  as  the  hock  test  is  made  by  holding  up  the 
limb,  with  the  hock  sharply  bent,  for  several  minutes,  then  the 
horse  is  started  suddenly.  In  case  of  spavin  the  first  few  steps 
are  very  lame.  Old  horses  without  spavin  may  respond  to  this 
test  and  so  lead  to  error  if  one  is  not  careful. 


UNSOUNDNESS  245 

Splints.— Splints  apperr  as  small  tumors  of  various  shapes 
and  sizes  along  the  metacarpal  bones,  usually  at  the  junction  of 
the  large  and  small  metacarpals.  They  are  generally  more  seri- 
ous when  located  near  the  knee.  Occasionally  there  appears 
what  is  known  as  a  pegged  splint,  in  which  the  growth  extends 
across  the  back  of  the  cannon,  beneath  the  suspensory  ligament. 
It  is  important  to  avoid  mistaking  for  a  splint,  the  nor- 
mal enlargement  on  the  inferior  extremity  of  the  inner  meta- 
carpal. 

The  lameness  which  results  from  splints  is  recognized  by  lo- 
cating the  splint  and  noting  sensitiveness  on  pressure  over  this 
point.  The  horse  walks  nearly  or  quite  "sound,"  but  trots 
very  "lame,"  especially  on  hard  ground,  lie  is  apt  to  get 
worse  after  long  exercise  and  is  worse  on  rough,  hard  road. 

There  is  a  natural  tendency  to  recover.  For  this  reason  lame- 
ness from  splints  is  rarely  seen  in  aged  horses. 

When  the  splint  appears  very  close  to  the  knee,  or  in  the 
pegged  form,  there  is  less  prospect  of  natural  recovery,  and, 
with  the  latter  form,  lameness  is  very  apt  to  be  permanent, 
unless  relieved  by  surgical  means. 

Curb. — A  curb  is  a  result  of  injury  or  strain  of  a  short  liga- 
ment at  the  back  of  the  hock  joint,  and  is  characterized  at  first 
by  a  hot,  sensitive  swelling  just  back  of  the  lowest  part  of  the 
hock  joint.  After  the  period  of  swelling  and  inflammation  sub- 
sides, there  is  apt  to  remain  a  hard  tumor,  particularly  on  what 
is  known  as  curby  hocks.  In  cases  of  young  animals  with  other- 
wise good  legs,  proper  treatment  may  reduce  the  enlargement  to 
slight  size  or  practically  remove  it. 

Capped  hock. — This  is  a  soft  enlargement,  on  the  point  of  the 
hock,  and  is  produced  by  bruises.  Some  horses  get  it  by  back- 
ing up  against  the  stalls  and  striking  so  as  to  injure  the  i)oint 
of  the  hock;  bruises  may  be  received  during  car  shipment.  The 
first  swelling  may  usually  be  reduced  by  prompt  treatment,  but 
upon  slight  injury  it  returns  and  after  several  attacks  is  apt 
to  be  permanent.  A  capped  hock  does  not  injure  a  horse  for 
actual  use,  ])ut  it  is  unsightly,  and  materially  reduces  sale  value. 
Shoe  boil. — Shoe  boil  appears  as  an  enlargement  on  the  jioint 
of  the  elbow  or  superior  extremity  of  the  ulna.  It  is  very  simi- 
lar to  capped  hock  in  cause,  character  of  structures  involved, 
and  subsequent  history.  Shoe  boils  are  unsightly  and  injure 
sale,  but  do  not  cause  lameness. 


246  VETERINARY  STUDIES 

Synovial  sacs. — The  ordinary  wind  puffs,  bog  spavins,  and 
thoroughpins  are  typical  illustrations  of  enlarged  synovial  sacs. 
Thej'  are  not  usually  the  cause  of  lameness  and  are  to  be  re- 
garded rather  as  blemishes  and  indications.  They  are  common 
in  overgrown  draft  colts  that  have  not  had  sufficient  exercise. 

Wind  puffs  are  found  just  above  the  ankles  and  in  mature 
horses  usually  indicate  too  much  hard  work. 

Bog  spavins  are  enlargements  of  the  synovial  sac  of  the  hock 
joint,  and  appear  on  the  inner  and  front  part  of  the  hock.  They 
are  often  hereditary. 

Thoroughpins  are  similar  to  bog  spavins  and  wind  puffs,  ex- 
cept in  location.  Thoroughpins  appear  at  the  upper  and  back 
part  of  the  hock.  They  may  or  may  not  connect  with  the  syno- 
vial sac  of  the  hock  joint. 

Open  joint  is  usually  the  result  of  puncture  of  the  synovial 
sac  and  the  entrance  of  bacteria,  which  cause  an  acute  inflam- 
mation, known  as  synovitis.  This  form  of  lameness  can  usually 
be  very  easily  detected,  and  the  cause  recognized.  It  is  very 
serious  under  all  circumstances,  and  frequently  results  in  death. 
The  veterinarian  should  be  called  at  once. 

Hygromas. — These  are  enlargements  of  serous  sacs  at  promi- 
nent points  and  due  to  injury.  They  are  found  at  the  elbow, 
knee,  external  angle  of  ilium,  point  of  the  hock,  "pin  bone," 
point  of  shoulder,  etc.  They  sometimes  have  thick,  hard  walls. 
A  common  example  is  found  at  the  knees  of  stabled  cows. 

Miscellaneous. — Corns  usually  appear  at  the  inner  heel  of  the 
front  foot — in  the  angle  between  the  bar  and  wall.  They  may 
be  caused  by  bruise  of  the  sole  but  more  commonly  by  lateral 
pressure  of  the  weight  from  above  upon  the  sensitive  laminte 
and  velvety  tissue  in  a  contracted  heel. 

They  appear  as  bruised  areas  under  the  sole  at  the  point 
mentioned.  The  wall  at  the  affected  heel  is  apt  to  show  ridges 
which  are  not  parallel  with  the  coronary  band.  A  horse  with 
a  corn  frequently  "points"  as  in  a  case  of  navicular  disease. 

In  case  the  bruised  area  becomes  infected,  pus  forms  and 
eventually  discharges  at  the  coronary  band.  The  case  is  then 
known  as  a  "quittor." 

Navicular  disease  is  a  slowly  developing,  chronic  affection  of 
the  navicular  articulation.  The  navicular  bone,  with  its  articu- 
lar cartilage,  the  deep  flexor  tendon,  and  synovial  membrane 
at  that  point  may  be  involved  in  the  inflammation  and  its  re- 


UNSOUNDNESS  247 

i5ults.  The  disease  is  more  common  among  light  harness  horses. 
It  is  detected  by  "pointing"  in  the  stabk's;  after  the  case  is  well 
developed,  lameness  grows  worse  if  the  horse  continnes  to  work 
and  generally  improves  with  long  rest  only  to  return  again 
with  work. 

The  history  of  navicular  trouble  is  significant.  Slow  and 
vague  in  its  onset,  the  lameness  is  variable  and  irregular  at 
first.     Later  the  horse  "goes  on  his  toes"  in  a  stilty  manner  and 


Fig.  86. — Navicular  Disease.     (M.  U.  E.) 

1.  Normal  navicular  bone. 

2.  p]xostosis   (bouv  enlargenicnt)   with  fracture. 

3.  Exostosis  with 'extensive  ulceration  of  the  articular  surface. 

4.  5,  6,  7.  Varying  types  of  exostosis. 

Stumbles  easily  if  both  feet  are  affected.  There  may  be  heat 
in  the  hollow  of  the  heels  and  pressure  of  the  thumb  in  this 
hollow  together  with  sharp  flexion  of  the  toe  causes  increased 
lameness  when  the  liorse  is  made  to  move. 

Dummy. — ^A  dummy  is  a  horse  with  a  l)rain  disease  which  is 
indicated  by  peculiar  attitude  and  stupid  actions.  The  liorse 
is  listless,  stands  with  his  licad  down,  jicrhaps  resting  it  on  the 
manger  and  fre(|ucntly  rests  one  foot  upon  the  coronet  of  the 
other.  He  drinks  with  his  mouth  deep  in  the  water;  walks  with 
his  head  low,  although  stepping  high  or  dragging  tiie  feet;  is 
unal)le  to  back;  and  is  subject  to  sudden  brain  disturbances 
such  as  unreasonable  fright  and  panic.  Such  a  horse  will 
usually  leave  the  front  legs  crossed  if  they  are  put  in  this  un- 


248  VETERINARY  STUDIES 

natural  position  by  the  examiner.  A  sound  horse  will  not  do 
this  unless  trained  to  do  so. 

Roaring,  ivhistling,  heaves. — These  disorders  of  the  respira- 
tory organs  have  been  previously  described  as  serious  and 
chronic  and  should  not  be  overlooked. 

Heart  disease. — This  trouble  is  indicated  by  violent  or  irregu- 
lar heart  action,  inability  to  stand  exertion,  etc. 

Ruptured  perineum. — Ruptured  perineum  is  a  tear  between 
the  rectum  and  vagina  in  a  mare  at  the  time  of  foaling  and  is 
very  objectionable.  Some  cases  are  curable  by  an  expert  surgi- 
cal operation. 


LECTURE  LII 
UNSOUNDNESS   {Continued) 

Examination. — An  examination  for  soundness  should  be  sys- 
tematic and  thorough,  although  it  may  be  rapidly  done.  Ex- 
amination should  be  made  with  a  horse  in  the  stall  and  as  he 
backs  out,  stands  at  rest,  and  moves  about.  It  is  usually  neces- 
sary to  both  see  and  feel  and  it  is  not  safe  to  trust  the  eyes  alone. 
In  the  stall  examine  to  see  whether  the  horse  cribs,  weaves  or 
points,  or  has  any  stable  habit  which  is  objectionable.  As  he 
backs  out  of  the  stall,  he  may  show  peculiar  use  of  the  hind 
legs  or  imperfect  control  due  to  disorders  of  the  nervous  sys- 
tem. Very  frequently  the  iirst  intimation  of  spavin  is  given 
as  the  horse  is  made  to  step  from  side  to  side,  particularly  when 
he  steps  toward  the  spavined  leg,  or  an  obscure  stringhalt  may 
be  detected  as  the  horse  backs  out  of  the  stall  or  comes  ont  of 
the  stable. 

At  rest. — Outside  the  stall  the  observer  should  observe  the 
attitude  again  for  a  favored  limb,  dummy,  cribber,  wind  sucker, 
poor  hearing,  bad  disposition,  etc.  Beginning  in  front,  examine 
the  ears  for  hearing,  for  tumors  that  may  develop  at  the  base, 
for  split  ears,  etc. 

In  examining  the  eyes  it  should  be  borne  in  mind  that  periodic 
ophthalmic  (moon  blindness)  recurs  at  intervals  and  leaves 
the  eye  more  or  less  nearly  normal  between  times.  The  eye 
may  show  a  weakened,  or  squinting,  or  hazy  appearance  that 
is  suggestive. 

The  nostrils  should  be  examined  for  ulcers,  scars,  or  dis- 
charges which  would  suggest  glanders.  Dishonest  dealers  some- 
times plug  the  nostril  with  sponges  to  prevent  the  appearance 
of  suspicious  discharge. 

The  teeth  should  be  examined  for  evidences  of  cribbing  shown 
by  the  rounding  of  tlie  incisors,  for  age,  and  for  a  condition 
commonly  known  as  parrot  mouth,  i.e.,  overhanging  upper  teeth, 
which  interferes  with  pasture  feeding. 

The  lips  should  be  examined  for  evidence  of  paralysis.     The 

249 


250  VETERINARY  STUDIES 

submaxillary  lymph  glands  under  the  lower  jaw  should  be  ex- 
amined particularly  with  reference  to  glanders.  (See  Glanders. 
Lecture  XLI.) 

Foul  breath  may  show  diseased  tooth  or  diseased  maxillary 
sinus. 

The  2)oll  should  be  examined  for  scars  or  other  evidences  of 
present  or  previous  poll-evil,  which  is  a  deep  discharging  sore 
like  fistulous  withers. 

The  withers  should  be  examined  for  scars,  for  discharging 
sores,  and  other  evidences  of  fistulous  withers. 

The  shoulders  should  be  examined  for  sweeny,  sore  neck,  and, 
particularly,  for  so  called  collar  boils.  The  latter  are  either 
flat  and  broad  or  more  prominent  tumors,  which  will  usually 
subject  a  horse  to  sore  shoulders  when  he  is  put  to  work. 

The  elbow  should  be  examined  for  shoe  boil ;  the  knee  for 
scars  or  what  is  commonly  known  as  "broken  knee,"  which 
indicates  that  the  horse  is  inclined  to  stumble,  and  also  for  knee 
spavin,  a  bony  enlargement,  usually  located  on  the  inside. 

The  cannon  or  shin  bones  must  be  examined  for  splints,  and 
behind  them  the  tendons  must  be  examined  for  evidences  of 
sprains  and  other  injuries,  which  are  usually  indicated  by  a 
thickening. 

Ankles  are  to  be  examined  for  evidences  of  interfering,  and 
fractures  or  other  injuries  of  the  sesamoid  bones  and  attached 
ligaments.  The  pastern  is  to  be  examined  for  ringbones,  side- 
bones,  and  evidences  of  the  operation  known  as  nerving.  In 
case  of  doubtful  sidebone  have  the  foot  lifted  and  then  examine 
it  again.  Evidences  of  nerving  are  found  in  scars  about  mid- 
way of  the  pastern  on  each  side  and  just  at  the  edge  of  the  back 
tendon.  The  sides  of  the  back  tendons  should  also  be  examined 
just  above  the  ankle  for  scars,  which  would  suggest  another  nerv- 
ing operation.  The  mere  fact  that  a  horse  has  been  nerved, 
whether  going  sound  at  the  time  of  examination  or  not,  is  a 
very  serious  objection.  This  operation  is  not  usually  resorted 
to  except  as  a  measure  of  last  resort,  and  it  does  not  in  any 
sense  cure  the  original  disease. 

The  feet  should  be  examined  for  evidences  of  contraction  at 
the  heels,  for  flatness  or  convexity  of  the  sole,  corns,  founder, 
navicular  disease,  thrush,  and  other  foot  diseases,  such  as  quar- 
ter and  toe  cracks,  and  serious  injuries  to  the  crown  of  the  hoof 
by  sharp  calks. 


UNSOUNDNESS  251 

In  examining:  the  feet,  the  shoe  should  usually  be  removed 
and  every  portion  of  the  sole  and  frog  examined  for  nail  punc- 
ture.    A  blacksmith's  sage  knife  is  best  for  the  purpose. 

While  passing  along  the  side  and  flank  the  breathing  should 
be  observed  to  determine  whether  it  is  even  and  regular,  or 
jerky,  suggesting  heaves.  The  flank  and  lower  i)art  of  the 
abdomen  must  be  examined  for  i)0ssible  ruptures. 

Stepping  behind  the  horse  compare  the  two  hips  for  evidences 
of  fracture.  A  horse  so  affected  is  commonly  described  as  being 
hipped  or  liiji-shot.  Tliis  unsoundness  is  due  to  fracture  of  a 
small  piece  off  the  external  angle  of  the  ilium.  It  does  not  in- 
terfere seriously  with  working  ability,  but  produces  a  very  awk- 
ward appearance  and  materially  lessens  value. 

The  /ior/.'.s'  must  be  examined  for  bog  and  bone  spavins,  thor- 
oughpins,  curl)s,  and  capped  hock.  The  same  examination  is 
made  of  the  cannon,  ankle,  and  pastern  as  for  the  front  limbs. 

In  motion. — The  horse  should  be  examined  wliile  walking  and 
trotting.  The  movements  of  the  neck  and  head  are  studied  as 
he  comes  toward  and  passes  by  the  observer,  the  movements  of 
the  limbs  being  noted  as  to  the  height  to  which  they  are  raised, 
and  the  bend  of  the  joints  (whether  easy  and  natural  or  other- 
wise). The  way  in  which  the  limb  is  carried  and  the  foot 
"lands"  upon  the  ground — whether  flat,  on  the  toe,  on  one  side, 
or  on  the  heel — -is  to  be  noted  and  considered.  As  the  horse 
passes  from  the  observer,  the  movements  of  the  hips  and  hind 
legs  are  noted  with  a  view  to  detecting  lameness  in  those  parts. 
To  bring  out  diseases  of  the  feet  examination  in  motion  on  hard 
road  or  pavement  should  be  made.  Then  if  there  is  uncertain 
lameness,  motion  in  deep  mud  or  in  snow  should  be  studied.  If 
such  conditions  are  not  available,  the  horse  should  be  made  to 
step  over  a  wagon  tongue  or  a  plank,  held  up  about  a  foot  from 
the  ground,  in  order  to  detect  or  make  more  prominent  possible 
soreness  or  lameness  in  the  shoulder  or  hip. 

Finally,  the  horse  should  be  given  vigorous  exercise  on  a  full 
stomach ;  for  instance,  a  run  to  a  heavy  wagon,  or  a  short  run 
uphill,  to  determine  whether  the  respiration  is  normal,  or  in 
otlier  words  to  test  his  "wind."  While  a  horse  is  at  rest  or  at 
light  exercise,  it  is  i)ossible  to  partially  disguise  abnormal  breath- 
ing; but  severe  exercise  on  a  full  stomach  will  usually  bring 
it  out. 

The  most   common   and  obvious  forms  of  unsoundness  are : 


252  VETERINARY  STUDIES 

Bad  eyes ;  especially  cataract ;  glanders  shown  at  the  nose ;  poll- 
evil,  just  back  of  the  ears,  at  the  top  of  the  neck ;  fistula  at  the 
withers ;  heaves  and  roaring,  shown  in  breathing ;  splints,  along 
the  cannon;  injured  tendons;  farcy  sores  on  limbs  or  body; 
ankles  bruised  from  interfering ;  sidebones  and  ringbones  at  the 
pastern;  navicular  disease,  corns,  founder,  cracks  in  the  hoof; 
fractured  hip  (hipshot)  ;  spavin  at  the  hock  in  front,  and  curb 
at  the  hock  behind. 

Lameness. — A  lameness  is  any  irregularity  of  the  gait,  re- 
gardless of  cause  or  degree  of  severity. 

Locating  the  lameness. — It  is  usually  quite  easy  for  any 
observer  to  see  that  an  animal  is  lame,  provided  the  lameness  is 
at  all  decided,  but  there  are  many  cases  where  lameness  is  so 
very  slight  or  complicated  that  it  is  difficult  even  for  an  expert 
to  locate  it. 

Examination  may  be  necessary  before,  during,  and  sometimes 
after  exercise. 

Side. — A  very  common  error  is  that  of  locating  the  lameness 
on  the  wrong  side.  The  head  and  weight  of  the  body  in  gen- 
eral, come  down  most  noticeably  with  the  sound  limb.  For  in- 
stance, a  horse  which  is  lame  in  the  left  front  leg  will  nod  and 
drop  the  head,  neck  and  front  quarters,  as  he  lands  upon  the 
right  front  leg. 

Gait. — Some  forms  of  lameness  are  detected  with  great  dif- 
ficulty when  the  animal  is  walking,  but  are  easily  seen  when  the 
horse  is  trotting.  It  is  usually  conceded  that  the  latter  is  the 
best  gait  for  diagnostic  purposes,  although  the  observer  should 
study  the  movements  at  both  walk  and  trot.  The  pacing  gait 
is  rather  confusing. 

General  examination. — The  horse  should  be  examined  at  rest 
and  when  he  is  unblanketed  in  the  stall.  He  may  "point"  or 
he  may  uneasily  raise  and  repeatedly  shift  the  same  foot,  indi- 
cating the  unsound  limb  and  even  the  location  and  nature  of 
the  trouble. 

The  horse  should  then  be  made  to  step  from  side  to  side,  and 
forward  and  back,  then  taken  out  and  observed  while  walking 
and  trotting,  coming  toward,  passing  by,  and  going  from  the 
observer,  the  latter  observing  carefully  the  movements  of  the 
entire  body  and  the  use  of  each  limb.  It  is  especially  important 
to  obsei-ve  the  head  and  hips  in  solving  the  first  problem  of 
locating  the  diseased  limb.     In  case  of  doubt,  circle  the  animal 


UNSOUNDNESS  253 

both  ways ;  he  may  show  plain  lameness  when  the  diseased  limb 
is  on  the  inside.  The  horse  should  be  tried  on  both  hard  and 
soft  ground  and  on  side  hill.  If  the  lameness  is  in  the  foot,  it 
is  most  marked  when  the  animal  travels  on  hard  ground.  When 
it  is  in  the  shoulder,  he  is  likely  to  travel  with  great  difficulty 
in  deep  mud  or  in  snow,  or  when  stepping  over  a  wagon  tongue. 

When  the  trouble  is  in  front  it  should  always  be  borne  in 
mind  that  the  front  foot  is  an  especially  common  seat  of  lame- 
ness, whereas  in  the  hind  leg,  trouble  is  most  common  at  the 
hock. 

Sometimes  unusual  combinations  are  confusing.  A  horse  lame 
in  both  front  or  both  hind  limbs  is  short  and  stilty  in  stride, 
carrying  his  feet  close  to  the  ground,  and  backing  with  dif- 
ticulty.  If  in  trotting  two  diagonal  limbs  are  lame,  the  whole 
body  rises  as  they  land  and  falls  as  the  sound  pair  land.  If  two 
limbs  on  the  same  side  are  lame  there  is  a  peculiar  see-sawing  of 
the  entire  body. 

Lameness  at  shoulder,  stifle,  and  hip  is  indicated  by  difficulty 
in  bringing  the  limb  forward  and  there  is  "swinging  leg  lame- 
ness. ' ' 

A  horse  affected  with  shoulder  lameness  often  rests  the  lame 
limb  on  the  toe,  with  the  knee  flexed  and  the  limb  directly  be- 
neath the  shoulder.  He  has  a  short  forward  stride,  and  a  swing- 
ing leg  lameness,  which  is  worse  when  he  travels  up  hill,  or  in 
mud,  and  often  shows  plainly  when  turned  short.  He  has  great 
difficulty  in  backing,  and  drags  the  limb. 


OBSTETRICS 


LECTURE  LIII 

OBSTETRICS 

Obstetrics  is  the  science  which  deals  with  the  birth  of  young 
animals.  The  female  organs  stndied  in  obstetrics  are:  ovaries, 
Fallopian  tubes,  vagina,  and  uterus. 

Ovaries. — These  are  two  small,  more  or  less  flattened,  spheri- 
cal organs,  suspended  in  the  front  part  of  the  broad  ligament 
(see   uterus)    in  the   sublumbar   region.      Their   function   is   tj 
develop,  mature,  and  discharge  the  ovules  or  eggs. 

Fallopian  tubes. — 
Two  slender  tubes  con- 
sisting of  mucous, 
nnisfular,  and  serous 
coats,  the  mucous  mem- 
brane being  contin- 
uous with  that  of  the 
uterus.  They  connect 
the  ovaries,  one  on  each 
side,  with  the  horns  of 
the  u  t  e  r  u  s.  The 
ovules  or  eggs  pass 
through  these  tubes 
on  their  way  to  the 
uterus. 

Uterus  (womb). — 
The  uterus  is  a  muscu- 
lar sack  small  in  non- 
pregnant animals  and  very  large  in  pregnant  animals — located 
partly  in  the  pelvic  cavity  and  partly  in  the  abdominal  cavity. 
Structure. — The  uterus  consists  of  three  layers  or  coats:  {a) 
outer  or  peritoneal;  (&)  middle,  muscular;  (c)  inner,  mucous. 
The  outer  (a)  is  the  thin,  delicate,  glistening  membrane,  the 
peritoneum,  which  lines  the  entire  abdominal  cavity  and  covers 
with  another  layer  every  organ  within  that  cavity. 

The  middle  coat  (&)  is  composed  of  two  distinct  sets  of  muscle 

254 


Fig.  87. — Generative  Organs  of  the  Mare. 

1,  ovaries;  2,  Fallopian  tubes;  6,  horn  of 
uterus  intact;  7,  horn  of  uterus  laid  open;  8, 
body  of  uterus;  9,  broad  ligament;  10,  cervix 
or  neck  of  the  uterus;  13,  outlet  of  the  ure- 
thra. 


OBSTETRICS 


255 


fibers.  The  outer  fibers  extend  lengtliwise,  and  tlie  inner  ones 
around  the  uterus.  The  muscular  coat  gives  strength  and 
support   to   the   womb    and   aids   in   expulsion   of   the   fetus   at 

birth. 

The  inner  coat  (c)  is  a  mucous  membrane  and  very  similar 
to  that  which  lines  the  mouth  and  whole  alimentary  canal.  This 
coat  has  especial  importance,  since  it  provides  for  early  nourish- 
ment of  the  ovum  and  later  develops  the  maternal  placenta  or 
afterbirth  which  gives  the  l)ond  of  union  l)ct\vcen  the  mother 
and     fetus     during 


gen- 


pregnancy. 

Shape. — In 
eral  the  body  of  the 
uterus  is  cylindrical 
and  divides  in  front 
into  two  branches. 
Each  branch  con- 
nects with  a  Fallo- 
pian t  u  b  e  a  n  d 
through  that  with 
the  ovary.  The 
body  of  the  uterus 
narrows  behind  to 
a  neck  which  pro- 
jects into  the  va- 
gina except  in  the 
sow.       The     cervix 


Fig.  88.- 


-Fetus  and  Fetal  Membranes  op  the 
Cow  AT  Mid-pregnancy, 

Uterus  opened  on  the  right  side,  exposing  fetus 
and  membranes.  Note  the  small,  light-colored 
bodies  (cotyledons)  which  connect  uterus  and 
mcndiranes.  8eo  also  Fig.  S9.  A,  uterus;  B,  cer- 
vix  (neck  of  uterus). 

(neck),     body    and 

horns  differ  greatly  in  the  various  domestic  animals,  e.g.  the 
cervix  in  the  cow  is  from  two  to  three  inches  long,  very  firm 
and  with  a  tortuous  canal.  The  sow  has  the  body  of  the  uterus 
short,  horns  long  and  the  cervix  not  very  distinct,  the  vagina 
and  uterus  being  more  nearly  continuous.  The  rectum  is  above 
the  uterus,  and  the  bladder  below  it. 

Supports.— The  uterus  is  held  in  place  by  four  ligaments 
which  are  partly  folds  of  the  peritoneum.  The  most  important 
of  these  are  the  broad  ligaments.  These  are  two  wide  folds  of 
the  peritoneum  witli  some  fibrous  and  muscular  tissue,  which 
are  attached  to  the  body  of  the  utcnis  and  its  horns,  one  on 
each  side  and  to  the  sublumbar  region  above.  A  third  liga- 
ment is  attached  al)ove  to  the  rectum,  and  a  fourth  below  to  the 


256 


VETERINARY  STUDIES 


floor  of  the  pelvis.     These  four  ligaments  all  give  support  to 
the  uterus  and  hold  it  in  position. 

Openings. — There  are  three  openings  into  the  uterus :  one 
behind,  opening  into  the  vagina,  i.e.  the  cervical  canal  through 
the  cervix ;  and  two  in  front,  for  the  Fallopian  tubes. 

Function. — The  function  of  the  uterus  is  to  receive  and  nour- 
ish the  ovum  and  mature  it  after  it  has  been  fertilized. 

The  ovum  attaches  to  the  uterine  wall  and  three  covering 
and  supporting  membranes  are  developed  around  it.     These  in 

order  from  without  in 
are  the  chorion,  allan- 
tois  and  ammion.  Here 
the  fetus  develops,  re- 
ceiving oxygen  and  food 
materials  from  the  ma- 
ternal uterine  walls, 
through  the  surroimd- 
ing  placental  mem- 
branes. There  is  no 
direct  circulation  from 
mother  to  fetus. 

In  the  cow,  sheep, 
and  goat,  contact  be- 
tween the  mother 's 
uterus  and  the  chorion 
is  by  about  60  to  100  large,  rounded  button-like  bodies  called 
cotyledons,  developed  from  the  mucous  membranes  of  the  uterus. 
Over  these  fit  cap-like  bodies  from  the  fetal  chorion.  The  mare 
has  a  very  different  relation  between  fetus  and  uterus.  Her 
uterine  mucous  membrane  is  provided  with  a  very  large  number 
of  tiny  pockets  into  which  fit  minute  capillary  tufts,  making  a 
practically  continuous  contact  between  uterus  and  chorion. 

Vagina. — This  is  a  membranous  tube  which  contains  much 
muscular  tissue  in  its  walls. 

Structure. — There  are  three  coats:  (a)  outer,  of  loose  con- 
nective tissue ;  (6)  middle,  muscular;  (c)  inner,  mucous.  Close 
to  the  cervix,  the  external  surface  is  covered  also  by  the  peri- 
toneum. 

Location. — The  vagina  is  located  in  the  pelvis  between  the 
rectum  above  and  the  floor  of  the  pelvis  below.  It  is  capable  of 
great  dilation  to  allow  the  passage  of  the  young  at  birth.     Be- 


B 

^B 

^B 

1 

^£ 

^^s 

^^w 

1 

m 

^s 

^B 

1 

|b 

^^^S 

^^^K 

■ 

jjg 

^^M 

1^^^ 

1 

Fig.  89. — Bovine  Cotyledons. 

A,  pedicle  of  uterine  cotyledon;  B,  B,  uter- 
ine cotyledon;  D,  fetal  cotyledon;  E,  fetal 
membrane. 


OBSTETRICS  257 

tween  the  uterus  and  vagina  the  connection  or  common  open- 
ing is  through  the  neck  of  the  uterus,  properly  the  cervix.  At 
this  point  the  uterus  narrows  greatly  and  is  composed  of  firmer 
tissue,  especially  in  the  cow.  As  the  time  for  delivery  ap- 
proaches this  narrow  canal  is  dilated  until  the  opening  is  large 
enough  for  the  young  animal  to  pass  through. 

Normal  period  of  gestation. — This  varies  from  two  years  in 
the  elephant  to  30  days  in  the  rabbit.  The  cow  carries  young 
about  283  days;  mare,  345  days;  sow,  119  days;  ewe,  149  days. 
All  these  may  vary  greatly.  Old  animals  usually  carry  longer 
than  young. 

Accidents  op  Pregnancy 

The  most  serious  accidents  of  pregnancy  are :  abortion,  reten- 
tion of  the  fetus,  and  volvulus  (twist  in  and  near  the  neck  of 
the  uterus). 

Abortion. — For  the  purpose  of  this  lesson,  abortion  may  be 
defined  as  any  premature  birth. 

Abortions  are  either  sporadic  or  infectious,  usually  the  latter. 

Sporadic  abortions  may  be  due  to  a  great  variety  of  condi- 
tions; e.g.,  death  of  very  weak  embryos;  strong  medicines,  espe- 
cially purgatives;  mechanical  injuries;  sudden  and  unaccus- 
tomed exercise ;  extreme  nervous  excitement ;  diseases  accom- 
panied by  cough  or  severe  pain  or  high  fever ;  disease  of  the 
uterus  and  lack  of  constitutional  vigor  in  either  sire  or  dam. 

Infectious  abortion  is  an  ^exceedingly  serious  disease.  The 
actual  abortion  should  be  considered  as  merely  one  of  several 
serious  symptoms  of  the  disease.  See  "General  results."  It  is 
due  to  contagium ;  i.e.  to  the  action  of  living  germs  upon  the 
uterus,  fetus,  and  placental  membranes. 

Infectious  abortion,  unlike  hog  cholera,  does  not  spread  rap- 
idly through  a  herd.  Cases  usually  come  at  irregular  intervals 
throughout  the  season  until  a  large  percentage  of  the  herd  may 
have  aborted.     See  next  Lecture. 

Symptoms. — Symptoms  of  approaching  abortion  depend  on 
the  stage  of  pregnancy,  and  are  frequeritly  obscure  or  even 
lacking  if  the  abortion  occurs  very  early.  Sometimes  there  is  a 
discharge  from  the  vagina  aiul  its  mucous  meml)rane  may  be 
dee'^ily  congested.  Slight  labor  pains  sometimes  appear  several 
hours  before  the  fetus  is  expelled  and  before  the  sac  is  rup- 
tured. Occasionally  tlic  animal  may  be  noticed  moving  around 
'v 


258  VETERINARY  STUDIES 

uneasily.  Ligaments  at  the  tail  head  on  each  side  relax  and 
drop.  The  udder  develops  prematurely,  especially  noticed  in 
heifers. 

General  results  of  abortion. — The  afterbirth  is  frequently 
retained  and  septicemia  ("blood  poisoning")  may  ensue  in  the 
absence  of  skillful  treatment.  Garget  may  appear,  which  seems 
to  be  associated  with  the  condition  of  the  uterus,  probably  by 
transfer  of  infection  from  the  discharge.  The  appetite  may  be 
impaired  or  lost.  The  patient  may  lose  flesh  or  she  may  come 
in  heat  frequently,  but  remain  barren. 

Sterility,  retention  of  afterbirth,  white  scours  in  young  calves, 
calf  pneumonia,  calves  born  weak  with  tendency  to  diarrhea 
may  all  be  features  of  infectious  abortion. 


LECTURE  LIV 
OBSTETRICS— Continued 

Infectious  Ahortion 

In  many  respects,  infections  abortion  is  the  most  serious  dis- 
ease confronting  the  American  breeder.  Those  responsible  for 
its  control  are  confronted  with  many  and  serious  difficulties. 
The  disease  is  insidious,  the  period  of  incubation  being  rather 
long.  There  is  no  satisfactory  means  of  individual  diagnosis 
and  prevention  is  uncertain.  Management  of  an  infected  herd 
is  tedious,  expensive,  and  results  often  unreliable. 

Causes. — Infectious  abortion  is  due  to  living  microorganisms, 
usually  bacteria.  It  is  evident  that  several  different  germs  are 
capable  of  causing  this  trouble,  and  if  this  be  true,  then  we  do 
not  have  a  specific  disease  due  to  one  specific  germ.  It  is  most 
common  in  cattle  at  five  to  seven  months,  but  may  occur  at 
any  time  after  a  few  weeks  of  pregnancy.  Cattle,  horses,  sheep, 
and  swine  are  all  subject  to  an  infectious  abortion,  due  to 
several  different  microorganisms.  The  virus  generally  accepted 
as  being  chiefly  responsible  for  abortion  in  cattle  and  swine  (the 
Bacillus  of  Bang)  appears  to  be  the  same,  although  the  disease 
apparently  does  not  spread  from  the  one  class  of  stock  to  the 
other.     In  mares  and  ewes,  however,  the  viruses  are  different. 

The  student  should  remember  that  the  act  of  abortion  is  only 
one  of  several  disastrous  symptoms,  as  taught  in  the  preceding 
Lecture,  and  not  in  itself  a  complete  disease. 

Abortion  in  horses,  swine,  and  sheep  is  less  common  and  less 
serious  than  in  cattle  at  present,  and  this  Lecture  will  treat 
chiefl}"  of  infectious  abortion  in  cattle. 

It  is  evident  that  infectious  abortion  may  be  spread  in  many 
ways.  It  is  most  easily  introduced  by  the  purchase  of  an  in- 
fected pregnant  cow  from  a  herd  in  which  the  disease  has  pre- 
vailed. A  cow  may  abort  one  or  more  times,  then  become  more 
or  less  immune  and  subsequently  carry  calves  to  full  term,  but 
remain  infectious  for  an  indefinite   period,  and  thus  prove  a 

259 


260  VETERINARY  STUDIES 

very  serious,  because  unsuspected,  source  of  spread.  Under 
natural  conditions,  infection  may  occur  by  way  of  the  respira- 
tory, digestive,  or  genital  tract  in  breeding.  The  afterbirth, 
discharges  from  the  womb  and  vagina,  and  manure  of  abortion 
calves  are  all  probably  infectious. 

Results. — A  serious  percentage  of  cows  which  abort  subse- 
quently become  sterile.  Most  cows  do  not  abort  more  than 
twice  and  thereafter  may  become  either  regular  breeders,  or 
shy  breeders  or  sterile,  or  they  may  become  immune  ' '  carriers, ' ' 
i.e.  raise  calves  but  remain  infectious.  Contamination  with  the 
virus  of  abortion  may  result  in  abortion,  or  in  a  birth  at  or  near 
full  term,  with  the  calf  weak  and  predisposed  to  diarrhea. 
Cows  which  abort  are  likely  to  retain  placenta  and  be  unthrifty 
for  a  long  time.  Some  contract  infection  of  the  udder  probably 
from  vaginal  discharge,  terminating  in  serious  case  of  garget; 
or  there  may  be  a  general  septicemia  or  blood  poisoning. 

Diagnosis. — ^We  have  first  the  history  of  an  unusual  number 
of  cows  in  a  herd  dropping  their  calves  prematurely.  Fre- 
quently the  vaginal  discharge  wdiich  accompanies  abortion  is 
dirty  in  appearance  with  shreds  of  tissue  and  a  foul  odor.  The 
mucous  membrane  of  the  vagina  may  become  congested  and  the 
lips  of  the  vulva  swollen  several  days  before  abortion  occurs. 
A  coming  abortion  in  heifers  is  often  indicated  by  marked  pre- 
mature development  of  the  udder,  and  the  ligaments  at  the  tail 
head  on  each  side  relax  and  drop.  Older  cows  are  apt  to  abort 
without  any  warning. 

There  are  two  serum  tests  which  give  useful,  but  limited  in- 
formation. In  a  general  herd  test  they  furnish  information  as 
to  the  general  condition  of  the  herd  with  reference  to  the  dis- 
ease. But  they  do  not  tell  whether  a  certain  cow  has  aborted 
or  will  abort  or  is  a  spreader  of  the  disease. 

Prevention. — It  is  necessary  to  bear  in  mind  the  probable 
cause  of  this  disease  and  the  common  methods  of  dissemination. 
A  farmer  owning  a  healthy  herd  should  not  purchase  cattle  of 
breeding  age  from  a  herd  in  which  this  disease  has  prevailed 
within  three  years.  He  is  safer  in  any  case  if  he  buys  unbred 
heifers  or  mature  cows  that  are  heavy  springers  with  good 
breeding  history.  He  should  not  do  public  service  with  a  herd 
bull  where  there  is  possibility  of  contamination,  nor  should  he 
use  a  neighbor's  bull  if  it  is  possibly  contaminated  with  this 
infection.     It  is  also  safer  policy  for  the  breeder  to  raise  his 


OBSTETRICS  261 

own  females  as  far  as  possible  and  purchase  young  males  that 
have  not  been  used. 

Mana-gement  of  an  aborting  herd. — Abortion  should  not  be 
allowed  to  occur  in  the  herd  stable  if  it  can  be  avoided.  The 
calf  and  afterbirth  should  be  buried  deeply  or,  better  still, 
burned.  Floors  and  partitions  and  other  contaminated  surfaces 
should  be  carefully  cleaned  and  disinfected.  In  case  the  calf  is 
mature  enough  to  survive,  its  manure  should  be  treated  as 
though  it  were  certainly  infectious. 

Some  outbreaks  of  what  seems  to  be  infectious  abortion  are 
apparently  gotten  rid  of  very  easily  under  a  treatment  which 
to  an  experienced  veterinarian  or  bacteriologist  would  be 
absurd;  but  as  a  rule  very  painstaking  work,  long  continued, 
is  essential  to  any  assurance  of  success.  An  owner  should  not 
undertake  the  treatment  of  a  considerable  number  of  animals 
unless  they  are  sufficiently  valuable  to  make  it  worth  while,  and 
he  realizes  that  he  has  a  hard  task  ahead  of  him. 

Sell  for  slaughter  females  that  have  ever  been  bred  and  which 
are  not  valuable  enough  to  justify  the  additional  work  and 
expense  of  treatment.  Cows  that  have  aborted  should  be  sold 
for  slaughter  only;  but  it  is  not  asually  advisable  to  sell  good 
cows  merely  because  they  have  aborted. 

Medical  treatment  is  now  generally  discarded  as  ineffective. 
There  is  no  reliable  cure.  Various  vaccines  and  serums  are  on 
the  market  and  are  well  advertised;  but  they  are  of  doubtful 
value.  There  is  a  living  virus  vaccine  which  appears  capable 
of  harm  by  dissemination  of  the  disease.  There  is  also  a  killed 
culture  vaccine  which  appears  to  have  little  protective  value. 
Neither  is  advised  as  yet  as  a  preventive  of  abortion. 

It  frequently  happens  in  affected  herds  that  valuable  cows 
abort  and  then  remain  sterile.  Others  are  infected  and  remain 
sterile  without  known  abortion. 

Many  of  these  choice  cows  can  be  cured  of  their  sterility  by 
expert  veterinary  treatment. 

AA'hen  a  cow  has  aborted  well  along  in  pregnancy,  the  after- 
birth should  be  removed  as  soon  as  it  will  come  away  easily. 
Cows  that  have  aborted  should  not  be  bred  until  the  discharge 
has  ceased  for  at  least  a  month  and  the  generative  organs  are 
normal  again. 

Males  should  be  used  with  caution.  For  cows  that  have  never 
aborted,  use  a  bull  tliat   has  had   no  chance  for  infection,  the 


262  VETERINARY  STUDIES 

bull's  sheath  to  be  disinfected  internally  before  and  after  each 
service.  If  possible,  use  a  different  bull  for  cows  that  have 
aborted,  he  also  to  be  disinfected  before  and  after  service,  but 
with  a  different  tubing  and  nozzle. 

In  any  herd  where  there  is  danger  of  this  infection,  calves 
should  be  born  in  clean  and  recently  disinfected  stalls  and  from 
clean  and  externally  disinfected  dams. 

Treat  the  stump  of  the  calf's  navel  cord  with  tincture  of 
iodin  in  a  cup  or  wide  mouth  bottle :  This  is  easier  to  do  with 
the  calf  on  his  feet.  Iodin  treatment  is  to  be  repeated  until  the 
cord  is  dry  and  hard.  Soak  it  several  minutes  at  each  treat- 
ment. Equal  parts  of  alum  and  boraeic  acid  may  be  dusted 
freely  over  the  cord  after  the  iodin  treatment.  It  is  important 
to  remember  that  a  calf  may  be  infected  early  in  life  through 
milk  from  dam  or  nurse  cow,  the  virus  coming  from  the  udder 
in  the  milk.  Or  the  young  calf  may  be  infected  from  external 
contamination  of  the  teat  and  udder  by  vaginal  discharge.  It 
is  safer,  therefore,  in  an  aborting  herd  to  wean  the  calf  early 
and  raise  it  on  pasteurized,  or  even  boiled,  milk.  Tliere  is  then 
less  risk  of  calf  scours  and  calf  pneumonia,  which  are  common 
in  such  herds. 

Calf-scours  serum  appears  to  give  good  results  as  a  preven- 
tive and  should  be  given  to  all  calves  in  affected  herds,  as  soon 
as  possible  after  birth,  in  addition  to  the  sanitary  precautions 
already  advised. 

Internal  disinfection  as  used  here  means  injection  into  the 
vagina,  not  uterus,  for  females  and  into  the  sheath  for  males. 
External  disinfection  for  cows  means  surface  in  general,  but 
especiall}'  around  and  under  the  tail  and  between  the  thighs ; 
for  bulls,  the  outside  of  the  sheath,  especially  around  the 
opening. 

For  internal  disinf ectioii  use  one  half  per  cent  solution  of 
Lugol's  iodin;  or,  for  simple  cleansing,  common  salt,  a  table- 
spoonful  to  the  gallon  of  water.  A  container,  a  funnel,  and  a 
few  feet  of  i/^-inch  rubber  tubing  with  a  short  smooth  nozzle  of 
some  kind  is  all  that  is  necessary  for  apparatus.  For  treating 
a  large  number  of  cows,  a  simple  container  for  a  gravity  appa- 
ratus is  very  convenient  and  cheap.  This  may  be  made  from  a 
large  galvanized  iron  pail  with  a  stopcock  at  the  bottom.  An 
old-fashioned  "shotgun"  milk  can  is  an  ideal  container,  since 
it  is  already  fitted  with  stopcock  at  the  bottom  and  has  a  glass 


OBSTETRICS  263 

gauge  at  the  side  where  the  amount  given  each  animal  may  be 
easily  read  off  as  the  fluid  lowers  in  the  can.  The  container  may 
be  very  conveniently  held  by  an  ordinary  snap  sliding  on  an 
overhead  wire  extending  across  the  stable  back  of  the  cows. 

Stables. — Frequent  cleaning  and  free  use  of  stable  disinfec- 
tants is  necessary  for  mangers,  partitions,  floors,  etc.,  with 
plenty  of  lime  in  the  gutter.  Manure  should  be  removed  and 
used  so  that  it  cannot  carry  infection  to  pregnant  cows.  Feed 
for  breeding  females  must  not  be  contaminated  by  discharges 
from  aborting  cows,  or  by  manure  from  calves  born  of  aborting 

cows. 

For  disinfection  of  the  cow  stable,  litter  should  be  cleaned 
out  of  the  mangers  and  stalls;  walls,  partition,  floors,  etc., 
should  be  thoroughly  scrubbed  using  plenty  of  water  and  then 
be  disinfected  by  means  of  corrosive  sublimate,  1  to  1000  in 
water,  or  copper  sulphate,  5  oz.  to  a  gallon  of  water,  or,  by 
corrosive  sublimate  in  fresh  whitewash  in  the  proportion  of  1 
lb.  corrosive  sublimate  to  1000  lbs.  of  water  (125  gallons). 

:\Iany  bulletins  on  abortion  have  been  issued  by  state  experi- 
ment stations  and  the  Federal  Bureau  of  Animal  Industry. 
These  may  be  easily  secured  and  should  be  consulted  for  details 
of  herd  management  and  individual  treatment. 

This  work  should  be  under  the  supervision  of  a  competent 
veterinarian  who  has  given  special  study  to  the  problems 
involved. 


LECTURE  LV 
OBSTETRICS  (Continued) 

Accidents  of  Pregnancy 

Accidents  of  pregnancy  are  nearly  all  serious  and  should  be 
handled  by  a  veterinarian  whenever  possible.  A  neighbor's 
meddling  has  killed  many  a  fine  cow  and  mare  that  could  have 
been  saved. 

Retention  of  the  fetus. — This  trouble  is  most  common  in 
cows.  The  period  of  retention  may  vary  from  normal  up  to 
years.  A  fetus  may  be  dead  and  mummified,  or  it  may  decom- 
pose. Aged  mares  sometimes  carry  beyond  the  normal  period 
for  delivery  and  then  give  normal  birth. 

Sijmptoms. — The  mother  may  show  labor  pains  at  normal 
time  and  all  other  symptoms  of  parturition  may  be  present. 
The  symptoms  soon  disappear  and  the  cow  goes  on  as  if  non- 
pregnant, but  does  not  come  in  heat. 

Causes. — Retention  of  the  fetus  is  due  to  such  causes  as  par- 
tial paralysis  of  the  uterus,  excessive  adhesions  between  fetus 
and  uterus,  deformed  pelvis,  and  torsion  of  uterus. 

Treatment. — At  the  normal  period  of  delivery  with  the  cow 
in  labor  and  not  progressing  properly,  the  veterinarian  should 
be  called,  to  dilate  the  cervix  and  force  delivery  if  indications 
justify  such  radical  procedure.  This  is  very  difficult  in  the 
cow  and  easier  in  the  mare.  If  the  cow  has  gone  safely  past 
this  period,  then  fatten  and  sell  her  for  beef. 

Volvulus  (twist). — A  twist  sometimes  occurs  in  and  near  the 
neck  of  the   uterus  and   makes  delivery   exceedingly   difficult. 

It  is  much  more  common  in  the  cow  than  in  the  mare,  and 
usually  occurs  near  the  termination  of  pregnancy. 

Symptmns. — Labor  pains  and  the  normal  symptoms  of  de- 
livery appear  at  the  usual  time.  If  not  relieved  serious  illness 
may  follow.  The  cow  becomes  anxious  and  restless,  her  respira- 
tion is  hurried.  She  shows  abdominal  discomfort,  and  if  not 
relieved  will  probably  die.     On  examination,  a  spiral  twist  of 

264 


OBSTETRICS  265 

the  uterus  is  easily  recofjnized  unless  it  be  far  forward  and  out 
of  reach — which  sometimes  occurs. 

Cause.— YoUulns  may  be  caused  by  the  patient  slipping  or 
falling,  and  especially  if  the  cow  or  mare  rolls  over,  late  in  the 
period  of  pregnancy.  Some  authors  think  it  may  be  due  to 
active  and  unusual  movements  of  the  fetus. 

Treatment.— U  the  twist  is  slight,  the  operator  may  be  able 
to  reduce  it  by  introducing  the  hand  into  the  uterus,  grasping 
some  portion  of  the  fetus,  and  causing  the  uterus  to  unwind  by 
a  strong,  twisting  motion.  Even  when  it  is  possible  to  intro- 
duce the  hand,  treatment  is  apt  to  be  a  slow  and  difficult  task. 
It  is  necessary  to  proceed  slowly  as  the  tissues  relax.  If  the 
case  is  at  all  difficult,  call  your  veterinarian  promptly.  Some- 
times it  is  necessary  to  throw  the  cow  or  mare,  then  introduce 
the  hand,  grasp  firmly  one  or  more  limbs  of  the  fetus,  and  have 
the  cow  rolled  in  the  opposite  direction  from  the  twist,  holding 
firmly  to  the  fetus  meanwhile.  If  the  operator  can  succeed  in 
getting  his  hand  into  the  uterus,  and  especially  if  he  can  get 
one  or  more  fetal  limbs  through  the  neck  of  the  uterus,  the 
twist  often  may  be  reduced.  ]Many  of  these  cases,  however,  are 
exceedingly  difficult  or  incurable. 

Accidents  of  Parturition 

The  most  common  accidents  are:  (a)  Infection;  and  inflam- 
mation of  the  uterus   (metritis);   (&)   inversion  of  the  uterus; 

(c)  tear  in  the  vagina;  followed  by  infection  and  vaginitis; 

(d)  retention  of  fetal  membranes;  (e)  hemorrhage;   (/)  mam- 
mitis   (garget). 

Metritis.— Inflammation  of  the  uterus  is  a  very  serious  dis- 
order and  apt  to  result  in  death  from  septic  metritis  or  peri- 
tonitis. The  symptoms  usually  appear  within  one  to  four  days, 
with  chill,  high  fever,  thirst,  abdominal  pain,  and  cold  extremi- 
ties— ears,  horns,  etc.— straining,  vaginal  discharge  and 
swollen,  discolored  vulva.  There  is  frequently  posterior  pa- 
ralysis.   Pressure  in  the  right  flank  is  very  painful. 

Inversion  of  the  uterus. — This  disorder  is  most  common  in 
the  cow,  and  may  be  partial  or  complete.  There  may  also  be 
partial  eversion  of  the  bladder  and  vagina.  It  may  be  due  to 
excessive  force  used  in  aiding  delivery,  or  to  failure  of  the 
uterus  to  contract  after  delivery. 


266  VETERINARY  STUDIES 

Treatment. — Cleanse  the  protruding  uterus  thoroughly  with 
hot  water  and  invert  it  over  the  hand  and  arm.  Be  careful  to 
smooth  out  each  fold  and  leave  the  uterus  in  a  natural  posi- 
tion. If  the  organ  is  greatly  swollen  and  heavy,  bathe  it  in 
cold  astringent  solutions,  like  strong  alum  water,  until  the  size 
is  sufficiently  reduced  to  permit  replacement.  A  clean,  com- 
mon washtub  is  very  convenient  for  bathing  the  soiled  and 
swollen  uterus. 

Bandaging  very  firmly  with  a  wide  roller  of  muslin  forces 
out  much  of  the  blood,  reduces  the  bulk,  and  allows  handling 
of  the  uterus  without  injury.  The  bandage  should  be  wide,  and 
be  rolled  from  both  ends.  To  put  on  the  bandage,  begin  with 
the  middle  of  the  bandage  at  the  end  of  the  uterus  and  carry 
the  ends  around  in  opposite  directions,  pulling  firmly  all  the 
time  so  as  to  force  the  blood  back  into  the  general  circulation. 
In  very  troublesome  cases  it  may  be  advisable  to  first  throw  a 
cow  carefully,  then  hoist  her  hind  parts  by  pulleys  and  ropes 
until  only  the  shoulders  and  neck  rest  upon  the  floor.  The 
rope  should  be  attached  by  hopples  or  otherwise  just  above  the 
ankles,  and  suitable  provision  made  so  as  to  avoid  injury  to  the 
skin  and  underlying  parts.  A  good  hopple  strap  will  usually 
do  very  well.  Ordinary  rope  could  be  used  with  several  thick- 
nesses of  heavy  cloth  or  a  flat  pad  of  oakum  inside  of  the  rope 
to  protect  the  skin.  In  this  position  the  uterus  of  a  very 
troublesome  case  may  usually  be  replaced  easily,  and  no  harm 
is  done  to  the  cow  if  she  is  carefully  handled.  After  replacing, 
it  is  sometimes  advisable  to  pack  the  uterus  with  cotton  and 
close  the  outlet  by  means  of  sutures  through  the  vulva,  or  to 
put  on  a  rope  truss. 

Finally  give  the  cow  3  oz.  tincture  of  opium  and  2  oz.  bromid 
of  potassium  in  i/^  pint  of  sirup.  Give  a  mare  two  thirds  of 
this  dose  and  the  ewe  one  eighth.  Repeat  the  dose  in  three 
hours  if  the  animal  is  still  straining.  If  necessary,  apply  rope 
truss  as  shown  in  classroom. 

Tear  or  bruise  in  vagina. — A  vagina  may  be  torn  above  or 
below  by  excessive  size  of  the  fetus,  by  faulty  position  of  the 
fetus,  or  by  excessive  force  used  in  delivery.  Infection  and 
inflammation  (vaginitis)  then  follow.  This  is  indicated  by 
unusual  swelling  of  the  vulva  with  dark  and  discharging  mu- 
cous membrane.  This  discharge  soon  has  foul  odor.  Slight  cases 
usually  make  prompt  recovery  under  hot  water  irrigation  or 


OBSTETRICS  267 

fomentation.  Tears  and  severe  bruises  must  have  veterinary 
service.  This  calls  for  immediate  operation  by  a  veterinarian, 
and  the  injury  is  much  more  dangerous  for  the  mare  than  for 
the  cow. 

Retention  of  the  placenta  (afterbirth)  .—This  trouble  is  most 
common  in  cows,  but  is  less  serious  for  cows  than  for  mares.  It 
is  caused  by  unusual  adhesions  between  the  placenta  and  the 
womb,  imprisonment  of  the  placental  tufts  in  the  corresponding 
cavities  of  maternal  cotyledons  and  by  a  mild  inflammation  due 
to  infection,  often  from  infectious  abortion. 

There  is  normally  a  short  period  of  exhaustion  following 
delivery.  After  this  period  the  uterus  should  recover  its  nor- 
mal tone  and  expel  the  afterbirth  and  accompanying  fluids. 
Note  the  order  of  development :  infection,  inflammation  with 
accompam'ing  swelling,  and  then  adhesion. 

Treatment. — For  the  mare  the  placenta  should  usually  be  re- 
moved within  twelve  hours  if  it  fails  to  come  away  naturally. 
If  the  cow's  afterbirth  can  be  removed  easily  and  without 
hemorrhage,  then  the  sooner  it  is  removed  the  better. 

Everything  in  this  work  must  be  done  carefully  and  with  a 
view  to  cleanliness.  Ifirst,  irrigate  the  vagina  with  an  antisep- 
tic, e.g.  one  half  per  cent  Lugol's  iodin,  and  disinfect  the  sur- 
rounding external  parts. 

As  nearly  as  possible  the  entire  placenta  should  be  removed 
by  introducing  an  oiled  hand  into  the  uterus,  gently  separating 
the  placenta  from  its  uterine  adhesions,  and  pulling  with  the 
other  hand  outside. 

If  a  cow's  afterbirth  does  not  come  away  easily  and  com- 
pletely and  there  be  no  urgent  reason  for  removal,  then  treat- 
ment should  be  directed  against  extension  of  infection. 

A  good  authority  recommends  iodoform  and  boracic  acid, 
equal  parts,  and  suggests  that  this  may  be  put  in  a  capsule  and 
the  capsule  either  left  to  dissolve  in  the  uterus  or  opened  and 
the  powder  scattered  in  the  uterus  by  hand.  The  purpose  of 
this  treatment  is,  of  course,  to  check  the  development  of  infec- 
tive organisms. 

The  patient  should  be  examined  from  time  to  time,  and  it 
will  usually  be  found  after  awhile  that  the  afterbirth  has  been 
released  and  will  come  away  easily.  In  some  cases  of  retained 
afterbirth  there  develops  a  rapid  necrosis  (death)  of  the  ma- 
ternal cotyledons,  in  which  case  the  cotyledons  themselves  may 


268  VETERINARY  STUDIES 

come  away  with  the  afterbirth  and  their  removal  cause  no  seri- 
ous harm. 

Hemorrhage. — This  is  rare  in  the  lower  animals.  It  is  de- 
noted by  rapidly  increasing  paleness  around  the  eyes  and  in 
the  mouth  and  by  quick,  feeble  pulse.  Blood  may  not  appear 
on  the  outside,  and  yet  the  bleeding  be  "extensive.  Give  3  oz. 
f.  e.  ergot  at  once,  in  4  oz.  sirup,  and  then  give  1  oz.  ergot  in 
2  oz.  sirup  every  hour  if  necessary,  up  to  a  limit  of  six  doses; 
meantime  pour  ice  water  over  the  back  and  loins. 


LECTURE  LVI 
DISORDERS  OF  THE  UDDER 

Garget  (Mammitis) 

Mammitis  is  an  inflammation  of  the  gland  tissue  and  other 
structures  composing  the  udder.  Some  congestion  and  harden- 
ing of  the  udder  is  probably  normal  at  about  the  time  of  par- 
turition. 

Causes. — Garget  (mammitis  or  mastitis)  is  usually  caused 
directly  by  germ  infection  or  injury,  aided  by  infection.  Germs 
probably  gain  entrance  in  many  cases  through  the  milk  ducts 
of  the  teats.  There  is  great  variation  in  the  severity  of  these 
cases.  Some  cases  of  garget  are  very  mild,  and  some  lead  to 
rapid  loss  of  the  udder. 

Many  cases  of  garget  are  the  result  of  infection  through  the 
teat  from  retained  afterbirth,  or  from  some  purulent  discharge 
from  the  vagina.  The  infection  from  a  retained  afterbirth  or 
from  the  vaginal  discharge  becomes  smeared  upon  the  teat-, 
bacteria  gain  entrance  into  the  milk  canal,  where  they  find 
favorable  conditions  for  multiplication  and  rapid  extension  up 
the  milk  canal  into  the  udder.  Some  cases  receive  their  infec- 
tion from  the  hands  of  milkers  who  have  milked  other  cows 
which  have  such  infectious  material  upon  the  teats  or  the 
udder.  In  other  cases  the  infection  may  have  been  carried  into 
the  milk  duct  by  milk  tubes. 

Many  preventable  causes  contribute  to  garget,  e.g.  excessively 
high  feeding,  cold  cement  floors,  high  door  sills  and  low  udders, 
washing  followed  by  chilling,  etc. 

Symptoms. — The  symptoms  of  garget  are  the  usual  symp- 
toms of  inflammation  in  any  soft  organ:  i.e.,  pain,  heat,  redness, 
and  swelling.  This  is  one  of  the  most  easily  recognized  diseases 
of  live  stock. 

Results. — Garget  usually  leaves  a  damaged  udder.  In  some 
cases  the  damage  may  be  extreme  and  in  others  slight ;  but  it  is 
probable  that  few  cases  are  ever  completely  restored  to  normal. 

269 


270  VETERINARY  STUDIES 

The  injury  to  the  milk-gland  structure  includes  various  de- 
generations, connective  tissue  hardening  and  permanent  enlarge- 
ment, abscess,  or  even  gangrene.  Development  of  gangrene  may 
be  detected  by  noting  that  the  part  which  has  previously  been 
hot  and  tender  becomes  cold,  dark  in  color,  and  insensitive. 

Prevention. — Cows  that  are  wisely  fed  seem  much  less  liable 
to  udder  troubles  at  the  time  of  calving.  Heavy  milkers  espe- 
cially should  be  carefully  fed  during  the  last  period  of  preg- 
nancy. The  food  should  be  laxative  in  character,  and  this  same 
method  of  feeding  should  be  continued  until  about  the  fourth 
day  after  calving,  when  the  grain  ration  may  be  gradually 
increased,  the  cow  being  put  on  feed  very  gradually  for  several 
days. 

In  case  of  a  valuable  cow  that  has  just  calved,  it  is  well  to 
disinfect  the  udder  and  teat  with  1  to  1000  bichlorid  in  water, 
which  may  be  washed  off  with  water.  If  possible,  this  disin- 
fection should  be  given  before  any  milk  is  drawn  after  calving, 
and  should  be  kept  up  for  a  week  in  the  ease  of  a  valuable  cow. 
It  seems  that  the  cow's  udder  is  most  liable  to  this  trouble  dur- 
ing the  first  week  or  so  after  calving.  Later  there  does  not  seem 
to  be  so  much  danger  of  garget. 

Milk  tubes  do  very  much  more  harm  than  good  as  a  rule, 
and  should  never  be  used  except  when  absolutely  necessary,  and 
then  only  after  thorough  disinfection  of  the  teat  and  boiling 
of  the  tube.  The  latter  must  not  be  handled  in  any  way  to 
infect  the  portion  which  is  to  enter  the  teat.  Care  should  be 
exercised  not  to  milk  a  cow  with  hands  that  have  been  contami- 
nated from  purulent  discharges  of  any  kind  or  with  any  kind 
of  infectious  material.  A  cow  with  garget  should  always  be 
milked  last. 

Milkers  should  clean  their  hands  thoroughly  for  the  sake  of 
simple  cleanliness  and  pure  milk,  if  for  no  other  reason,  and  in 
addition  for  the  very  good  reason  that  they  are  then  not  liable  to 
carry  infection  which  may  cause  garget  in  the  udders  of  valu- 
able cows. 

Floors,  door-sills,  etc.,  should  be  as  little  likely  as  possible  to 
injure  udders.  A  cow  with  very  long  udder  should  be  so  placed 
in  the  stable  as  to  avoid  injury  from  tread  by  another  cow. 

Treatment. — The  diet  should  be  light  and  laxative.  Light 
feeding  during  the  last  few  weeks  before  calving  is  a  good 
preventive  measure  in  any  case. 


DISORDERS  OF  THE  UDDER  271 

If  intcriial,  or  vaccine,  treatment  of  any  kind  is  needed  it 
should  be  given— or  at  least  directed— by  a  veterinarian.  In 
most  cases  the  owner  can  safely  give  nitrate  of  potash  (salt- 
peter), 2  ounces  at  a  dose,  with  1/2  pound  Epsom  salts,  three 
times  a  day,  each  dose  dissolved  in  a  quart  of  water. 

For  external  treatment  of  the  udder,  apply  hot  water  freely 
for  long  periods  of  time ;  e.g.  twice  a  day  2  or  more  hours  at 
each  treatment.  The  water  should  be  used  as  hot  as  it  can  be 
comfortably  handled— it  is  easy  to  scald  an  udder— and  should 
be  used  very  freely.  This  hot-water  treatment  may  be  applied  to 
good  advantage  by  putting  a  sling  around  the  cow's  body  under 
the  udder  and  in  front  of  the  hips  to  support  the  udder.  Four 
holes  may  be  cut  for  the  teats,  and  woollen  cloths  packed  around 
the  udder  to  hold  the  heat  and  moisture.  The  hot  water  can 
then  be  poured  in  from  above  or  be  thrown  against  the  pack- 
ing from  below  by  means  of  a  small  dipper.  The  object  is  to 
treat  the  udder  with  moist  heat  for  a  long  period  of  time. 

After  each  water  treatment  rub  the  udder  dry  and  apply  a 
light  dressing  of  olive  oil.  Long-continued,  moderate  rubbing 
and  handling  of  the  udder  is  beneficial.  This  is  best  accom- 
plished by  first  milking  dry  and  then  a  combined  rubbing  and 
gentle  kneading  action  with  the  hands.  This  massage,  if  not 
unreasonably  severe,  is  helpful,  and  should  be  given  freely  sev- 
eral times  a  day  and  for  15  minutes  or  more  at  each  treat- 
ment. 

Udder  Diseases  and  Accidents 

Injuries. — Udders  and  teats  are  often  injured  by  barbed  wire, 
for  example,  or  by  being  tread  upon  in  the  stable  by  a  cow  in 
the  next  stall;  and  these  injuries  require  careful  treatment 
usually  by  a  veterinarian. 

Treatment. — In  general  such  wounds  should  be  trimmed,  well 
soaked  in  a  mild,  hot  antiseptic,  like  hot  saturated  boracic  acid 
solution,  and  then  covered  with  an  antiseptic  powder.  In  case 
but  little  tissue  has  been  destroyed,  it  may  be  well  to  partly 
or  wholly  close  the  wound  and  cover  a  generous  portion  of  the 
teat  with  surgeons'  adhesive  tape.  Tears  into  the  milk  duct 
require  skillful  surgical  treatment,  and  the  teat  may  often  be 
saved  in  good  shape.  The  owner  should  not  insert  a  milk  tube 
except  as  a  last  resort.     It  is  often  safer  to  trust  to  long  con- 


272  VETERLNARY  STUDIES 

tinued   hot  mild   antiseptic   treatment   and   gentle   massage   to 
reduce  the  swelling  and  re-open  the  duct. 

Fistula. — This  is  a  small  opening  in  the  side  of  the  teat,  which 
opening  connects  with  the  milk  duct  and  usually  leaks  milk  at 
least  during  milking.  It  is  just  an  unclosed  portion  of  an  old 
wound. 

Treatment. — When  the  cow  is  dry,  sterilize  the  teat  with  tinc- 
ture of  iodine,  then  with  a  very  slender  pointed  and  sharp  knife 
that  has  been  boiled  and  carefully  handled  to  avoid  infection, 
rim  out  the  old  skin  edge,  so  as  to  get  a  fresh  raw  edge  for 
healing;  or  sear  very  slightly  and  superficially  in  the  fistula 
with  a  hot  wire. 

After  this  treatment,  sterilize  the  wound  and  teat  again  with 
the  iodine,  and  bandage  it  with  adhesive  tape,  covering  plenty 
of  the  teat.  This  must  not  be  tight  enough  to  interfere  with 
the  circulation  and  should  usually  be  left  in  place  several  days. 

Teat  obstruction. — This  may  be  due  to  a  stricture  or  narrow- 
ing of  the  canal  as  the  result  of  an  injury.  Many  cases  are  due 
to  small  growths  of  various  forms,  wliich  result  from  a  mild 
infection.  They  often  form  while  the  cow  is  dry  and  are  found 
at  the  next  milking.  Many  of  these  cases  can  be  cured  by  a 
veterinarian's  skillful  surgical  operation. 

Warts. — In  case  warts  cause  trouble,  they  may  be  removed  in 
various  ways,  as  by  cutting  them  off  with  sharp  shears,  taking 
a  bit  of  normal  skin  all  around  the  wart,  or  by  tying  them  off 
by  a  stout  thread  close  to  the  teat. 

Hard  milker. — Otherwise  choice  cows  are  often  sold  or  killed, 
because  they  are  hard  milkers.  The  difficulty  in  these  cases  is 
usually  superficial,  the  end  of  the  milk  duct  opening  being  too 
small.  In  many  cases  this  can  be  cured  by  careful  dilation  with 
a  slender  cone  of  smooth  hard  wood  or  metal. 

Sterilize  the  teat  with  tincture  of  iodine.  Boil  the  dilator  ten 
minutes  and  handle  in  a  way  that  avoids  contamination.  Insert 
the  dilator  carefully,  and  leave  in  place  between  milkings. 
Caution  is  necessary  to  avoid  over-dilation  and  consequent  leak- 
age. The  veterinarian  uses  special  dilators  or  makes  a  small 
cross-shaped  incision  in  the  outlet  by  a  special  instrument. 

Cowpox. — Cowpox  is  a  contagious  disease  and  apparently  due 
to  a  filterable  virus  which  is  very  closely  related  to  or  identical 
with  human  smallpox  virus.  Sheep-pox  is  probably  an  entirely 
different  affection.     This  trouble  may  be  brought  into  a  herd  by 


DISORDERS  OP  THE  UDDER  273 

recently  vaccinated  persons.  Thereafter,  the  disease  is  spread  in 
the  herd  chiefly  by  the  hands  of  milkers,  but  may  be  transferred 
from  cow  to  cow  by  other  means. 

The  period  of  incubation  is  from  four  to  seven  days.  Then 
there  is  a  little  fever  and  mild  general  symptoms  of  slight  ill- 
ness. There  soon  appear  a  few  nodules  on  the  udder  and  teats, 
the  size  of  a  pea  or  smaller.  In  a  day  or  two  these  change  to 
vesicles  (blisters)  which  contain  a  thin,  clear  fluid.  At  eight  or 
ten  days  the  centers  of  the  vesicles  become  depressed  and  the 
contents  become  purident   (pus). 

A  dry  scab  gradually  forms  and  falls,  leaving  the  typical 
pitted  scar. 

The  sores  heal  nicely  unless  injured  in  milking.  Small,  slow 
healing  ulcers  may  be  caused  in  this  way. 

Treatment. — Little  treatment  is  necessary  beyond  very  careful 
milking,  unless  the  vesicles  are  ruptured  and  the  raw  surfaces 
injured,  e.g.,  in  milking.  Careful  handling  and  a  little  vaseline 
or  lanoline  are  then  needed. 


LECTURE  LVII 
DIFFICULT  PARTURITION  (DYSTOKIA) 

Nature's  plan. — ^When  the  delivery  occurs  according  to 
nature's  evident  plan,  the  ligaments  of  the  pelvis  relax;  the 
water  bag  appears  through  the  neck  of  the  uterus  and  finally 
outside  the  vagina;  the  neck  and  vagina  gradually  dilate  to 
accommodate  the  fetus,  which  presents  first  the  apex  of  a  wedge 
or  cone. 

Normal  presentations. — We  recognize  two  normal  presenta- 
tions, viz.,  the  anterior,  in  which  the  two  front  feet  and  the  nose 
appear  with  the  fetus  resting  upon  its  sternum,  and  the  posterior, 
in  which  the  two  hind  legs  and  tail  appear  with  the  fetus  resting 
on  the  sternum. 

Variations  from  these  cause  difficulty  in  delivery. 

Cause. — The  cause  of  difficult  parturition  may  lie  with  either 
the  mother  or  the  fetus,  though  more  commonly  with  the 
latter. 

If  the  fault  lies  with  the  mother,  it  is  usually  because  of 
premature  delivery;  extreme  narrowness  and  closeness  of  the 
pelvic  outlet;  volvulus;  deformities  of  the  pelvis  (sometimes 
fracture);  tumors  within  the  pelvis;  or  induration,  hardening, 
of  the  uterine  neck.  Sometimes  the  trouble  is  due  to  excessive 
accumulations  of  fat  within  the  pelvis. 

If  the  difficulty  lies  with  the  fetus,  it  is  because  of  faulty 
presentations,   excessive  size,  monstrosities,  or  deformities. 

Common  faulty  presentations. — Faulty  anterior  presentations 
may  be :  head,  or  head  and  neck  doubled  back ;  two  feet,  or  feet 
and  legs  back ;  or  the  neck  and  one  front  limb  back ;  or  the  neck 
and  both  front  limbs  back. 

Faulty  posterior  presentation  may  be:  one  limb  back  and 
doubled  at  the  hock  or  stifle ;  or  both  limbs  back  with  one  flexed 
at  each  of  these  points,  or  both  flexed  at  the  same  joint,  which 
may  be  either  hock  or  stifle.     Various  other  false  presentations 

may  occur. 

274 


DIFFICULT  PARTURITION  (DYSTOKIA) 


275 


Fig.  90. — Presentations.     (B.  A.  I.) 
A  and  B,  normal;  C,  D,  E,  F,  common  abnormal  presentations. 


276  VETERINARY  STUDIES 


Assistance 


What  may  be  needed. — There  is  probably  no  trouble  with 
farm  stock  where  trained  and  experienced  veterinary  assistance 
is  more  urgently  needed. 

Call  your  veterinarian  promptly,  if  one  is  available.  Do  not 
let  all  the  neighl)ors  try  it  first  and  ruin  all  chances  for  the 
veterinarian's  success — especially  with  mares. 

If  no  competent  veterinarian  is  available,  then  the  owner  must 
do  the  best  he  can  for  himself,  or  with  the  aid  of  a  careful  and 
experienced  neighbor.  Plenty  of  bland  oil,  e.g.  linseed,  may  be 
required;  two  small  window  cords  with  smooth  loops  in  one  end 
of  each  loop  to  loop  around  limbs ;  two  similar  ropes  with  short, 
sharp  hooks  in  end  to  hook  in  underjaw  or  ej^e  socket  or  leg ;  a 
pair  of  small  combination  pulleys,  possibly  an  embryotomy  knife, 
large  trocar  and  cannula,  some  antiseptic — e.g.  creolin — to  be 
used  in  4  per  cent  solution  for  hands,  instruments,  and  ropes. 
These  should  be  kept  on  hand  and  ready. 

Suggestions. — Do  not  interfere  until  the  water  bag  has  rup- 
tured, unless  labor  pains  have  continued  for  several  hours  and 
the  water  bag  does  not  appear.  Then  examine  by  rectum  and 
note  location  of  fetus.  Possibly  it  may  not  yet  be  even  in  posi- 
tion for  delivery.  In  that  case  if  you  cannot  have  veterinary 
service  leave  the  cow  alone  and  await  normal  delivery.  Examine 
by  rectum  every  twelve  hours  or  so  to  note  progress.  If  the 
cow  is  strong  and  the  calf  alive  it  may  be  born  naturally  a  day 
or  two  after  the  first  false  labor  pains. 

However,  if  the  first  examination  by  rectum  shows  the  calf 
well  advanced  and  presenting  for  delivery  and  no  progress  being 
made  then  examine  by  vagina  and  cervix.  There  may  be  a 
vohiilus.  See  Volvulus  in  preceding  lessons.  If  the  water 
bag  ruptures,  in  a  natural  way,  and  the  head,  for  example, 
should  present  without  the  feet,  or  the  head  and  one  foot,  or  if 
one  hind  foot  presents  and  not  the  other,  or  any  evidently  faulty 
presentation  occurs,  then  it  is  time  to  call  your  veterinarian, 
and  plan  for  assistance. 

If  you  cannot  have  expert  help  then  clean  and  oil  the  arm 
and  examine  carefully  to  learn  the  cause  of  trouble  and  position 
of  fetus.  Then  decide  what  you  will  do  and  how.  The  rectum 
should  also  be  examined  as  the  hand  goes  into  the  vagina,  and  if 
distended  should  also  be  emptied. 


DIFFICULT  PARTURITION   (DYSTOKIA)  277 

The  patient  should  stand  or  lie  with  head  do^vnhill.  It  is 
much  easier  to  operate  with  the  patient  standing.  Occasionally 
it  is  of  great  advantage  to  have  the  patient  on  one  side  or  the 
other  or  on  her  back  for  a  time  so  as  to  place  the  missing  part 
on  the  upper  side.  Be  patient  and  not  in  too  great  haste. 
When  missing  members  are  secured  and  all  is  ready  to  pull, 
pour  plenty  of  oil,  or,  in  the  absence  of  oil,  warm  water,  into 
the  uterus  and  vagina  by  means  of  a  funnel  and  rubber  tubing. 
The  parts  that  will  offer  friction  are  probably  dry  by  this  time, 
and  should  be  freely  oiled  or  moistened.  Clean,  non-irritating 
oil  is  better. 

It  is  frequently  necessary  to  shove  the  fetus  forward  into  the 
uterus  in  order  to  secure  and  straighten  some  missing  parts. 
Tearing  the  mother  is  an  accident  that  must  be  carefully  avoided 
on  account  of  probable  blood  poisoning  (septic  infection). 

"When  one  part  presents,  and  others  are  to  be  secured,  or  when 
one  has  been  secured  and  it  is  desirable  to  return  it  into  the 
uterus  to  secure  another  part,  make  sure  of  progress  gained  by 
attaching  a  rope  to  the  part  secured.  If  the  patient  cannot  be 
made  to  stand,  have  her  on  the  side  opposite  the  missing  part, 
which  thus  comes  on  top.  "Work  between  labor  pains,  and,  when 
all  ready  to  pull,  the  assistance  should  be  given  moderately  and 
while  the  mother  is  straining.  Great  force  is  seldom  justified 
either  by  necessity  or  by  results. 

Dropsies. — Sometimes  the  retarded  delivery  is  due  to  large 
accumulations  of  fluid  in  the  brain  cavity  (hydrocephalus)  of 
the  fetus  or  within  the  abdominal  cavity  (ascites),  or  to  a  general 
accumulation  of  fluids  or  gas  beneath  the  skin  in  the  connective 
tissue  and  also  in  the  abdominal  cavity  (general  dropsy).  In 
these  eases  the  difficulty  may  be  overcome  by  tapping  the  brain 
and  squeezing  the  soft  bones  together,  or  tapping  the  abdominal 
cavity  and  allowing  the  fluid  to  escape.  A  large  trocar  attached 
to  rubber  tubing  is  convenient  for  this  operation. 

Gaseous  distention. — Difficulty  in  delivery  may  be  due  to  an 
excessive  accumulation  of  gases  within  the  body  of  a  dead  and 
decaying  fetus,  and  the  obvious  treatment  is  to  tap  with  trocar 
or  knife  and  allow  gas  to  escape. 

Embryotomy. — If  it  becomes  necessary  to  open  the  fetal  body 
or  remove  one  or  more  of  the  fetal  limbs,  and  veterinary  help  is 
not  available,  the  operator  must  know  that  these  are  difficult 
operations  and  observe  certain  precautions. 


278  VETERINARY  STUDIES 

Beware  of  injuring  the  maternal  parts;  be  patient  and  work 
slowly. 

In  case  of  twins,  both  presenting  at  the  same  time,  force  one 
back  into  the  uterus  and  deliver  one  at  a  time.  Avoid  all  un- 
necessary dissections,  which  are  usually  very  tedious,  exhausting 
to  the  operator,  and  mother  as  well. 

Always  save  the  skin,  leaving  enough  to  cover  the  bones  and 
rough  parts  of  the  fetus,  and  to  pull  on. 

Removing  a  fore  linib. — Take  the  limb  that  is  presenting, 
attach  cord  and  draw  out,  as  far  as  possible ;  slit  the  skin  from 
as  near  the  top  of  the  scapula  as  possible  to  the  knee  or  pastern 
by  means  of  an  embryotomy  knife,  and  dissect  the  skin  loose 
from  the  limb,  largely  by  fingers  or  with  the  aid  of  a  thin  bladed 
case  knife  wdth  a  square  end ;  then  cut  last  the  skin  around  the 
knee  or  pastern.  Next  cut  the  muscles  between  the  limb  and  the 
sternum.  By  twisting  and  pulling  at  the  same  time,  the  limb 
can  then  be  removed  entire,  leaving  the  skin  attached  to  the 
shoulder.  Do  the  dissecting  with  one  hand,  while  the  other 
pulls  on  the  skin  outside.  The  skin  gives  an  object  to  pull  by, 
and  protects  the  parts  of  the  mother  from  bones.  It  also  keeps 
the  soft  parts  of  the  fetus  from  rolling  up  as  an  obstruction 
when  pressed  against  the  parts  of  the  mother. 

Removing  the  head. — If  the  head  can  be  brought  outside  the 
vulva,  and  there  is  good  reason  for  removing  it  (which  is  not 
often),  cut  the  skin  around  the  neck,  back  of  the  ears,  and 
dissect  the  skin  loose  from  the  muscles  by  the  hand  or  by  a  thin 
bladed  case  knife  with  square  end,  using  a  knife  to  cut  the 
connective  tissue  bands  that  interfere,  as  far  as  the  operator 
can  reach.  Then  cut  the  cord  on  top  of  the  neck,  the  cord  that 
supports  the  head,  and  also  the  muscles  around  the  vertebra?. 
Strong  pulling  and  twisting  on  the  head  will  usually  bring  away 
head  and  neck,  leaving  a-  quantity  of  skin  to  cover  remaining 
vertebra?  and  to  assist  in  pulling. 

Removal  of  the  hind  limbs. — This  is  done  on  the  same  general 
principle  as  for  the  fore  limb.  Supposing  the  limb  is  present- 
ing, cut  across  the  pelvic  articulation  of  the  limb  on  the  inside 
so  as  to  sever  the  ligament  which  holds  the  femur  strongly  to 
the  pelvis.  Slit  the  skin  from  this  point  to  the  hock  or  pastern 
according  to  the  case.  Dissect  the  skin  loose  from  the  limb,  as 
directed  for  the  fore  limb.  Then  by  strong  pulling  and  twisting 
the  limb  can  be  torn  loose  at  this  joint. 


DIFFICULT  PARTURITION   (DYSTOKIA)  279 

It  is  not  always  necessary  to  remove  both  liind  legs.  "With 
one  out  of  the  way  the  other  can  sometimes  be  straightened  or 
the  body  of  the  fetus  removed  with  the  other  straightened  for- 
ward in  the  uterus.  The  soft  organs  may  often  be  removed 
from  the  body  of  the  fetus  to  advantage,  and  then  delivery  be 
accomplished  easily.  In  some  cases  it  is  sufficient,  and  easier,  to 
disarticulate  at  the  hock  instead  of  at  the  pelvis. 

Caesarian  section.— Removal  of  the  fetus  through  the  flank 
or  median  line  of  the  belly  is  done  sometimes,  but  only  as  a  last 
resort,  more  commonly  and  successfully  done  with  cows  and  sows 
than  mares.  This  should  only  be  attempted  by  an  expert,  unless 
the  plan  is  to  save  only  the  fetus.  In  the  latter  ease  the  work 
must  be  done  very  rapidly.  This  operation  is  often  performed 
on  sows  and  is  reasonably  safe  for  them. 


MEDICINES 

LECTURE  LVIII 
COMMON  MEDICINES 

Common  measurements: 

A  dime  weighs  about  40  grains,  a  nickel  80,  a  quarter  100, 
a  half  dollar  200,  a  dollar  400  grains.  One  half  dollar  and  a 
dime,  e.g.,  would  weigh  about  half  an  ounce  or  a  dollar  and  a 
nickel  would  weigh  approximately  an  ounce. 

Teaspoon  holds  about  1  fluid  dram  (Vg  oz.). 
Tablespoon  holds  about  4  drams  (14  oz.). 
Dessert  spoon  holds  about  3  drams. 
Teacup  holds  about  6  oz. 

Giving  medicines. — Internal  medicines  may  be  given  to  do- 
mestic animals  in  the  form  of  liquid  drench,  gelatine  capsule 
ball,  or  dry  powder ;  or  may  be  mixed  with  honey  or  molasses 
and  smeared  on  the  tongue.  Some  medicines  are  given  under 
the  skin  by  hypodermic  syringe  and  some  by  injection  into  a 
vein.  In  giving  a  drench,  remember  that  a  horse's  mouth  and 
throat  are  very  sensitive  and  more  easily  injured  or  irritated 
than  the  human.  Taste  the  medicine  before  giving  it,  if  there  is 
doubt  about  its  being  too  strong.  Powders  should  be  finely  pul- 
verized, and  must  not  be  caustic  or  irritating.  Balls  should  be 
in  the  shape  of  a  cylinder  about  2  inches  long  and  i/o  to  %  of 
an  inch  in  diameter.  They  should  be  wrapped  in  thin  paper 
and  oiled.  They  must  be  reasonably  soft  and  pliable,  and  the 
horse  should  be  offered  water  immediately  after  swallowing 
them. 

Drenching. — In  giving  a  drench  the  patient's  head  must  not 
be  held  too  high,  the  face  should  be  nearly  horizontal,  with  the 
nose  just  a  little  higher.  If  the  head  is  too  high  swallowing  is 
difficult.  The  operator  must  not  be  in  a  hurry.  The  medicine 
should  be  given  in  small  quantities  on  top  of  the  tongue,  as  far 
back  in  the  mouth  as  possible,  and  the  horse  should  be  given 
plenty  of  time  to  swallow.  If  the  horse  is  obstinate  about  swal- 
lowing, pour  a  tablespoonful  of  water  into  the  nose  after  medi- 

280 


COMMON  MEDICINES 


281 


cine  is  poured  into  the  mouth.  ]\Iedicines  should  not  be  given 
through  the  nose  because  of  danger  of  choking,  and  of  causing 
pneumonia.  For  supporting  the 
head  to  give  a  drench,  a  rope  may 
be  tied  to  the  noseband  of  halter 
and  thrown  over  the  beam — never 
tied,  but  held  by  an  assistant.  Bet- 
ter still,  a  cloth  loop  may  be  passed 
around  the  upper  jaw  back  of  the 
front  teeth  and  through  the  nose- 
band of  the  halter  in  such  way  that 
it  cannot  slip  off.  This  cloth  loop  is 
fastened  to  the  overhead  rope, 
which  should  be  held — not  tied. 
Medicines  may  be  given  when  the 
patient  is  lying  down,  but  the  oper- 
ator must  be  careful  not  to  pour 
out  any  medicine  when  the  patient 
is  about  to  struggle  lest  choking 
occur.  Plenty  of  time  should  be 
taken. 

A  bottle  of  rubber  or  horn,  or  a  dose  syringe,  is  much  pref- 
erable to  a  glass  bottle,  which  may  break  readily,  and  cut  the 
mouth. 

Cathartics 


Fig.     91, — Holding     Horse's 

Head  for   Drenching. 

(M.  H.  E.) 

Note  cloth  loop  under  nose- 
band. 


Aloes. — Cathartic,^  laxative,-  or  bitter  tonic,  depending  upon 
the  dose  given,  is  very  reliable  and  satisfactory  for  horses,  but 
less  so  for  ruminants.  It  is  very  soluble  in  alcohol  and  boiling 
water,  but  imperfectly  so  in  cold  water,  and  usually  requires 
15  to  20  hours  for  operation.  It  is  often  desirable  to  combine 
it  with  one  fourth  its  weight  of  ginger,  and  give  it  in  conjunc- 
tion with  nux  vomica  in  case  the  bowels  are  torpid.  Large  rec- 
tal injections  of  warm  water  may  be  given  until  the  physic  acts. 

Doses.— Cattle,  1  to  2  oz. ;  horses,  2  to  8  drams ;  sheep,  1  to  2 
drams;  hogs,  1  to  2  drams. 

These  doses  may  be  administered  in  a  ball  with  ginger  and 
lard  or  molasses,  or,  as  a  drench,  in  water  or  sirup. 

Epsom  salts    (sulphate  of  magnesia). — This  is  a  saline  ea- 

*  Cathartic,  moderately  vigorous  physic. 
'Laxative,  mild  physic. 


282  VETERINARY  STUDIES 

thartic,  which  causes  a  large  secretion  of  fluids  from  the  intes- 
tinal walls,  thus  rendering  the  bowel  contents  very  fluid.  It 
is  very  soluble,  for  it  will  dissolve  in  its  own  weight  of  warm 
water.  This  is  a  very  satisfactory  laxative  or  cathartic  for 
cattle  and  sheep,  but  not  so  good  for  horses.  Epsom  salts  is 
useful  in  small  doses  for  horses  in  feverish  conditions. 

j)oses. — Cattle  take  for  cathartic  one  to  three  pounds;  sheep 
and  hogs  take  one-eighth  to  one  fourth  pound.  It  is  frequently 
desirable  to  add  one  sixth  the  total  weight  of  powdered  ginger 
and  give  as  a  drench  and  it  is  better  to  give  rather  dilute 
drenches;  e.g.  the  cow's  dose  should  be  dissolved  in  two  to  three 
pints  of  water,  and  the  others  in  proportion. 

Raw  linseed  oil. — Raw  linseed  oil  is  used  in  veterinary  prac- 
tice for  diluting  stronger  medicines,  for  making  liniments  and 
various  applications  for  external  use,  and  it  is  administered 
internally  as  a  laxative  or  cathartic,  depending  upon  the  dose 
used.  It  is  very  safe  and  but  slightly  irritating  for  horses, 
cattle,  sheep  or  swine. 

Boses. — Cattle  take  two  to  four  pints;  horses,  one  to  three 
pints;  sheep  and  hogs  take  one  fourth  to  one  pint. 

Rectal  injections  of  warm  water  may  follow  the  dose  of  oil, 
and  it  is  desirable,  if  there  is  sufficient  time,  to  prepare  horses 
by  several  warm  bran  mashes  before  giving  the  oil. 

Stimulants  and  Tonics 

Alcohol.^ — Alcohol  is  a  difl:'usive  stimulant,  diuretic,  antispas- 
modic, and  diaphoretic.  Large  doses  are  narcotic.  Medicinal 
doses  check  spasmodic  conditions  of  involuntary  muscle  fibers, 
stimulate  the  heart  and  lungs,  equalize  circulation,  and  tem- 
porarily overcome  depression.  Alcohol  is  soluble  in  all  pro- 
portions in  water,  and  should  be  diluted  at  least  four  times  for 
internal  use. 

Doses. — Cattle,  two  to  four  ounces;  horses,  one  to  two  ounces; 
sheep,  one  half  ounce;  hogs,  one  fourth  to  one  half  ounce  well 
diluted  as  above. 

Aromatic  spirits  of  ammonia. — This  is  a  quick,  very  useful 
and  typical  stimulant.     It  consists  of  ammonia  carbonate,  am- 

^  A  diuretic  stimulates  the  kidneys  and  increases  the  flow  of  urine.  A 
diaphoretic  stimulates  perspiration.  An  antispasmodic  relieves  crampy 
conditions,  especially  of  involuntary  muscle  fibres. 


COMMON  MEDICINES  283 

monia  water,  alcohol,  water,  and  various  aromatics.  It  quickly 
stimulates  the  heart,  lungs,  and  digestive  organs,  and  increases 
bronchial  secretions,  etc.  It  is  antacid  and  leaves  few  harmful 
after  effects.  It  is  very  useful  in  cases  of  exhaustion,  sunstroke, 
colic,  hoven,  and  in  certain  coughs.  The  dose  for  horses  and 
cattle  is  about  one  ounce  in  half  a  pint  of  water.  Sheep  and 
swine  take  about  one  eighth  as  much. 

Camphor. — Camphor  is  commonly  known  as  camphor  gvun. 
Spirits  of  camphor  consists  of  the  gum  dissolved  in  alcohol,  in 
a  strength  of  ten  per  cent.  The  gum  is  readily  soluble  in  alco- 
hol, ether  and  chloroform,  and  but  slightly  soluble  in  water. 
Used  externally  in  liniments,  it  has  first  a  mildly  stimulating 
and  then  slight  local  anesthetic  effect.  The  vapor  kills  fleas, 
moths,  bugs,  etc.  Internally  it  is  a  useful,  safe,  and  dependable 
stimulant  to  the  vital  centers  in  cases  of  great  depression,  shock, 
or  collapse. 

In  urgent  cases  for  which  camphor  is  most  commonly  used  it 
should  be  dissolved  in  olive  oil  and  given  by  hypodermic  injec- 
tion. The  dose  for  a  horse  is  about  one  dram  dissolved  in  four 
drams  of  olive  oil — about  two  drams  of  the  solution  to  be  in- 
jected at  each  place. 

Gentian. — Powdered  gentian  root  is  a  stomachic,^  and  tonic. 
It  promotes  appetite,  increases  the  secretions  and  improves 
digestion.  It  has  some  value  also  as  a  vermifuge ;  -  but  it  is 
especially  useful  where  a  simple,  bitter  tonic  is  needed,  as  for 
highly  fed  stock  "off-feed,"  or  where  debility  follows  an  acute 
disease  like  influenza  or  pneumonia.  It  is  helpful  in  other 
cases  of  debility  which  are  accompanied  by  poor  appetite  and 
digestion. 

Horses  take  one  half  to  one  ounce  and  cattle  one  or  two  ounces. 

Ging-er. — Ginger,  as  usually  seen,  is  in  the  powdered  root — 
or,  rather,  rhizome.  This  is  another  stomachic  and  stimulant. 
It  is  very  useful  for  mild  digestive  disturbances.  It  is  often 
combined  with  i)urgatives  as  an  aid  and  to  prevent  griping  and 
depression. 

It  is  especially  important  with  the  salines,  like  epsom  salts, 
given  in  full  doses. 

Horses  take  about  one  ounce,  and  cattle  two  to  four  ounces. 

*  Stimulates  normal  activities  of  tlie  stomach. 
^  E.xpels  worms. 


LECTURE  LIX 
COMMON  MEDICINES  (Continued) 

Antiseptics 

Boracic  acid. — Boracic  acid,  a  non-irritating,  antiseptic  pow- 
der or  crystals.  Boracic  acid  is  mainly  used  externally  either 
in  solution  (about  3  per  cent)  or  as  dry  powder  dressing  for 
wounds.  Sometimes  it  is  used  internally  for  colts  and  calves 
which  have  diarrhea.  Boracic  acid  is  soluble  in  26  parts  cold 
water,  in  3  parts  boiling  water,  or  in  6  parts  alcohol.  For  solu- 
tions, use  the  crystals. 

Doses. — Colts  and  calves  take  10  to  30  grains  in  sirup  three 
times  a  day. 

As  an  outward  application  for  wounds  and  sores,  the  acid  may 
be  mixed  with  half  its  bulk  of  iodoform. 

Carbolic  acid. — Carbolic  acid  deodorizes  and  kills  germs 
(germicidal).  In  strong  solutions  it  is  irritant,  caustic,  and 
locally  anesthetic.  Internally  it  is  at  first  a  stimulating  and 
afterwards  a  depressing  narcotic,  poisonous  in  sufficient  dose 
and  strength.  It  is  used  more  commonly  as  an  external  dis- 
infectant, in  2  to  5  per  cent  solutions.  Dilute  solutions  kill 
external  parasites.  Carbolic  acid  is  useful  in  the  treatment  of 
ringworm  used  as  10  to  15  per  cent  solution  in  glycerine  or 
linseed  oil.  It  is  not  so  commonly  used  as  a  dressing  in  surgi- 
cal work  as  formerly — usually  dispensed  from  the  drug  stores 
as  a  95  per  cent  solution  of  the  crystallized  drug. 

Corrosive  sublimate  (bichlorid  of  mercury). — This  is  a  caus- 
tic, and  irritant  poison.  It  is  used  externally  as  a  caustic  and 
antiseptic.  Strong  solutions  and  ointments  produce  very  severe 
blisters,  and  frequently  destroy  the  hair  follicles. 

It  is  chiefly  used  as  a  germicide.  For  this  purpose  it  is 
greatly  diluted.  Corrosive  sublimate  is  cheap  and  very  satis- 
factory for  disinfecting  buildings,  and  other  purposes  where 
large  quantities  must  be  used.  Dilute  solution  destroys  lice 
and  itch  mites  in  the  proportion  of  fifteen  grains  to  a  pint  of 

284 


COMMON  MEDICINES  285 

water.     For  antiseptic  and   disinfecting   purposes,   it   may  be 
used  four  to  seven  grains  to  the  pint. 

lodin.— lodin  occurs  as  bluish  black,  heavy  crystals,  readily 
soluble  in  alcohol  and  ether,  and  but  slightly  soluble  in  water, 
although  it  dissolves  in  water  readily  if  potassium  iodid  is  added. 
Tincture  of  iodin  is  a  solution  of  iodin  and  iodid  of  potash  in 
alcohol  and  contains  about  7  per  cent  iodin.  Lugol's  solution 
is  composed  of  iodin,  5 ;  iodid  of  potash,  10 ;  water,  100,— giving 
5  per  cent  iodin. 

Iodin  is  one  of  our  most  useful  and  dependable  disinfectants 
and  germicides  for  surgical  work,  wound  treatment,  etc.  It  is 
especially  valuable  in  skin  disinfection  as  for  castration,  or  in 
treatment  of  the  navel  cords  of  the  new  born.  For  skin  dis- 
infection, navel  cords,  etc.,  the  tincture  is  used  in  full  strength. 
Lugol's  solution  is  useful  and  reliable  for  disinfectant  pur- 
poses, diluted  in  water  at  from  2  to  4  per  cent.  For  some  pur- 
poses it  is  used  still  more  dilute  as  in  abortion  and  sterility 
work.  When  iodin  is  used  externally  by  repeated  treatment  as 
a  liniment  for  sprains,  bursal  enlargements,  arthritis,  etc.,  its 
slow,  mild,  but  persistent,  irritating  and  stimulating  action  is 
very  useful.  It  is  also  very  eifective  as  a  fungicide  as  in  ring- 
worm. 

Iodin  is  used  internally  for  actinomycosis  (see  Lecture 
XXXII),  where  it  is  given  internally  in  the  form  of  iodid  of 
potash  or  it  may  be  injected  as  the  tincture  or  as  Lugol's  solu- 
tion by  hypodermic,  directly  into  the  diseased  mass. 

Iodin  in  the  form  of  iodid  of  potash  is  useful  also,  when  given 
to  pregnant  dams  to  prevent  goiter  in  young  pigs,  and  lambs, 
and  to  prevent  hairless  pigs,  etc. 

When  used  internally  in  excess,  the  warning  symptoms  are : 
catarrhal  conditions  at  eyes  and  nose,  scurvy  skin,  digestive  dis- 
turbances, and  refusal  of  food. 

Iodoform. — This  is  used  for  external  and  local  application. 
It  prevents  infection  of  wounds  and  acts  as  a  local  antiseptic. 
Iodoform  is  useful  as  a  dressing  for  wounds,  especially  after 
they  have  commenced  to  heal.  It  may  be  used  alone  or  mixed 
with  twice  its  bulk  of  powdered  boracic  acid  and  dusted  over 
the  wound  surface. 

Common  Hme. — Common  lime  is  an  irritant,  it  neutralizes 
acids  and  is  astringeiit.  Saturated  solution,  which  is  very 
dilute,  is  useful  in  diarrheas  and  indigestions  of  young  animals, 


286  VETERINARY  STUDIES 

and  may  be  given  with  milk  quite  freely.  Carron  oil  (lime- 
water  and  linseed  oil  in  equal  parts)  is  an  old  and  useful  appli- 
cation for  burns.  Whitewashing  is  a  satisfactory  method  of 
disinfecting  and  cleaning  up  outbuildings,  including  stables. 
For  this  purpose,  fresh  chlorid  of  lime,  one  half  pound  to  the 
gallon  may  be  added  with  advantage. 

Sodium  chlorid  (common  salt). — Common  salt  is  an  essential 
article  of  food,  restorative,  and  antiseptic.  Very  large  doses 
are  cathartic  and  more  or  less  irritating.  It  is  useful  as  a 
throat  wash,  diluted  to  5  per  cent  solution  in  w^ater.  As  normal 
salt  solution  (about  one  tablespoonful  to  one  gallon  of  water),  it 
is  an  ideal  preparation  for  mechanical  cleaning  of  sensitive  sur- 
faces and  cavities,  e.g.,  eye,  vagina  or  uterus.  For  any  such 
purpose  it  is  a  good  cleanser  and  less  irritating  than  plain 
water. 

Sodium  hyposulphite  and  sodium  sulphite. — These  are  anti- 
septic and  deodorant ;  and  especially  valuable  for  internal  ad- 
ministration, to  check  fermentation  and  septic  processes  in  the 
stomach  and  intestines,  and  are  therefore  valuable  in  conditions 
of  diarrhea,  indigestions,  and  hoven  or  bloat.  Both  the  sulphite 
and  the  hyposulphite  are  readily  soluble  in  water  and  are  not 
likely  to  do  any  harm. 

Doses. — Horses  and  cattle  take  8  to  10  oz. ;  of  the  sulphite 
sheep  and  swine  take  4  to  8  drams.  The  doses  of  hyposulphite 
are  about  half  as  large  as  for  the  sulphite.  These  doses  are  to 
be  given  as  drenches,  well  diluted,  and  repeated  three  times 
daily.  Smaller  doses  may  be  given  every  half  hour  in  cases  of 
bloat. 


LECTURE  LX 
COMMON  MEDICINES  {Continued) 

Diuretics 

Saltpeter  (nitrate  of  potash). — Saltpeter  is  very  soluble  in 
water,  warm  or  cold.  It  is  mildly  antiseptic,  and  has  slight 
cathartic  effect.  It  is  strongly  diuretic;  it  increases  secretion 
from  bronchial  tubes ;  it  is  alterative,  a  febrifuge  ^  and  useful 
in  the  treatment  of  all  classes  of  animals.  For  alteratives  and 
febrifuge  effect  it  is  given  in  about  half  the  doses  that  are  given 
to  stimulate  the  kidneys. 

Doses. — Cattle  and  horses  for  diuretic  effect  take  one  half  to 
two  ounces;  sheep  and  swine,  one  half  to  two  drams.  These 
doses  are  given  in  the  drinking  water  or  as  a  drench. 

Sweet  spirits  of  niter. — Stimulant  much  like  alcohol  or  ether ; 
it  is  antispasmodic  and  increases  the  excretion  from  skin,  lungs, 
and  kidneys.  Very  large  doses  are  narcotic.  It  is  very  useful 
in  cases  of  spasmodic  colic  and  it  is  a  convenient  heart  stimu- 
lant. 

Doses. — As  a  stimulant  and  antispasmodic,  horses  and  cattle 
take  two  to  four  ounces ;  hogs,  two  to  four  drams.  It  is  decom- 
posed by  water,  and  should  not  be  mixed  with  other  medicines 
until  just  before  its  use.  It  is  given  as  a  drench  with  water  or 
in  sirup.  As  an  antispasmodic  it  may  be  given  to  advantage 
with  either  opium  or  chloral  hydrate. 

Oil  of  turpentine  (common  turpentine). — Stimulant,  anti- 
spasmodic, antiseptic,  and  destroys  parasites,  both  external  and 
internal.  It  is  readily  absorbed  when  swallowed  and  is  excreted 
by  the  lungs,  skin  and  kidneys.  Medicinal  doses  stimulate  and 
overdoses  irritate  the  mucous  membrane  of  these  organs.  For 
medicinal  purposes  it  is  used  in  indigestion,  and  in  certain  con- 
ditions of  diarrhea  and  tympanites  (bloating)  ;  it  is  a  very  use- 
ful medicine  in  these  conditions  and  one  that  is  usually  at  hand. 

*  A  febrifuge  reduces  fever, 

2S7 


288  VETERINARY  STUDIES 

It  is  practically  insoluble  in  water;  soluble  in  ether,   alcohol 
and  chloroform  and  dilutes  well  in  linseed  oil. 

Doses. — Horses  take  1  to  3  ounces  and  cattle  2  to  6  ounces 
two  or  three  times  a  day.  The  dose  for  sheep  and  swine  should 
be  about  1/6  of  these  quantities. 

Narcotics  and  Sedatives 

Chloroform. — Stimulant,  antispasmodic,  anodyne,^  anesthetic. 
Its  stimulating  effect  resembles  that  of  alcohol,  but  is  less  pro- 
nounced and  more  temporary.  Applied  externally,  it  evapo- 
rates rapidly  and  is  cooling;  but  is  very  irritating  when  applied 
externally  and  prevented  from  evaporating. 

Chloroform  is  very  useful  in  colic,  cough,  and  other  spasmodic 
conditions  given  internally  with  eight  to  ten  times  its  bulk  of 
raw  linseed  oil  or  milk  and  well  shaken. 

It  is  very  slightly  soluble  in  water,  but  dissolves  freely  in 
alcohol,  ether  or  turpentine,  and  is  useful  in  spasmodic  colic. 

Doses. — Horses  and  cattle  take  two  to  four  drams  repeated 
every  two  to  three  hours,  if  necessary  till  the  patient  staggers. 
Sheep  and  hogs  take  one  half  to  one  dram  repeated  frequently 
as  for  horses  and  cattle. 

Sodium  bromid. — Small  white  crystals,  readily  soluble  in 
water.  This  medicine  is  usually  considered  as  the  least  toxic, 
least  irritating  to  the  stomach  and  the  most  hypnotic  ^  of  the 
bromids. 

It  acts  as  a  nerve  depressant  especially  on  the  motor  centers. 

The  bromids  are  often  combined  with  chloral  hydrate  and  are 
used  to  control  nervous  conditions  with  excessive  motor  activity, 
as  in  convulsive  conditions. 

Doses. — Horses  and  cattle  take  one  half  to  two  ounces. 

Opium. — Medicinal  doses  relieve  pain  and  spasmodic  condi- 
tions, reduce  congestion  and  inflammation ;  check  intestinal  se- 
cretions and  peristaltic  movements ;  and  with  some  animals  pro- 
duce sleep.  The  various  preparations  of  opium  are  used  espe- 
cially for  the  purpose  of  relieving  pain.  Opium  is  a  typical 
anodyne  (pain  reliever),  but  there  are  very  painful  conditions 
that  arise  in  practice  under  which  it  should  never  be  given, 
which  it  is  not  thought  practical  to  explain  in  this  short  lecture 

'  An  anodyne  relieves  pain.     An  anesthetic  removes  sensation. 
^A  hypnotic  produces  sleep. 


COMMON  MEDICINES  289 

further  than  tliat  the  person  who  is  giving  opium  preparation 
of  any  kind  to  any  domestic  animal  must  not  forget  that  it 
checks  intestinal  secretion  and  peristaltic  movements  of  the 
intestines,  and  in  this  way  may  cause  decided  constipation  at 
just  a  time  when  this  would  be  serious. 

DOSE  HORSES     CATTLE       SHEEP        HOGS 

Morphine  sulphate  . .  .  3-5  gxs.  3-8  grs.  1/2-2  grs.  1/2-2  grs. 
Tincture     opium     (hiu- 

danum)     1-2  ozs.         1-3  ozs,  2-6  drs.  2-6  drs. 

The  tincture  should  be  diluted  with  water  or  sirup  the  same 
as  for  alcohol. 

Morphin  is  an  active  principle  of  opium,  and  has  the  essen- 
tial physiological  properties  of  opium.  Cattle  and  sheep  take 
very  large  doses.  Morphin  and  various  preparations  of  opium 
are  sometimes  employed  in  spasmodic  colic  and  may  be  com- 
bined with  stimulants  or  anodynes  like  ether,  sweet  spirits  of 
niter  or  chloral  hydrate.  It  is  usually  advisable  to  give  a  laxa- 
tive soon  after  the  opium.  All  opium  preparations  must  be 
used  with  great  caution,  even  in  relieving  pain.  They  may  mask 
important  sj-mptoms  and  by  arresting  secretion  and  excretion, 
they  may  do  more  harm  than  good. 

Astringents 

Alum  (potassium  sulphate). — An  astringent  and  styptic.^ 
This  is  not  much  used  internally  in  veterinary  practice.  Within 
recent  years  very  large  doses  have  been  used  internally  and  with 
good  results  in  laminitis.     (See  Lecture  XLVI.) 

Alum  is  soluble  in  cold  water,  1  :*9,  and  very  soluble  in  hot 
water.  It  is  antiseptic,  astringent  and  mildly  caustic,  locally 
it  coagulates  albumin  and  checks  secretion.  In  the  circulation, 
alum  constricts  the  capillaries. 

It  is  more  commonly  used  externally  for  its  astringent  and 
mild  caustic  action  on  profuse  granulations,  and  "weeping" 
surfaces,  and  for  its  antiseptic  and  astringent  effect  in  stopping 
leakage  of  synovia  from  an  open  joint  with  small  puncture. 

Alum  is  a  common  ingredient  of  astringent  and  antiseptic 
dusting  powders. 

Dose. — The  usual  dose  for  internal  use  for  horses  and  cattle 
is  1  to  4  drams,  well  diluted. 

'  A  styptic  checks  hemorrhage,  aids  coagulation. 


290  VETERINARY  STUDIES 

Burnt  alum  is  common  alum  from  which  the  water  has  been 
driven  off  by  heating. 

It  is  quite  astringent,  somewhat  caustic,  and  is  sometimes  used 
on  excessive  granulations  in  an  open  wound. 

Tannic  acid  (tannin). — This  is  a  very  light,  yellowish  pow- 
der obtained  from  oak  galls.  It  is  soluble  in  water  and  glyc- 
erin, a  powerful  astringent  and  styptic. 

It  coagulates  albumin,  checks  secretion  locally  where  applied, 
and  is  but  slightly  irritating. 

Tannic  acid  is  often  used  on  mucous  membranes  for  its  astrin- 
gent effect  in  checking  the  local  secretion,  as  in  certain  diar- 
rheas when  a  non-caustic  astringent  is  needed.  Externally,  tan- 
nic acid  is  used  on  superficial  collar  and  other  harness  sores, 
dusted  on  as  a  powder,  or  dissolved  in  water  or  glycerin,  about 
2  ounces  to  the  pint.  Tannic  acid  dissolved  in  glycerin  is  very 
useful  for  sore  and  chapped  teats. 

Dose.— The  internal  dose  is  1  to  3  drams  in  solution  for  horses 
and  cattle.  Its  chief  use  for  the  stockman  will  be  for  external 
application. 

Miscellaneous 

Collodion. — Collodion  is  a  solution  of  gun  cotton  in  ether  and 
alcohol.  Flexible  collodion  contains  castor  oil  and  Canada  bal- 
sam, also,  and  is  better  for  most  veterinary  uses  than  plain 
collodion.  It  must  be  kept  in  a  tight  bottle  and  not  exposed  to 
an  open  flame. 

It  is  used  only  as  an  external  application  and  is  very  useful 
in  minor  surgery. 

When  painted  over  a  dry  surface,  it  dries  promptly  and  leaves 
a  thin  adherent  and  protective  covering  that  is  not  sticky.  This 
gives  excellent  protection  against  infection  and  minor  injury  to 
superficial  wounds.  It  is  useful  to  cover  small,  clean  wounds, 
cracked  and  chapped  teats,  etc. 

Other  medicines  are  often  added  in  order  to  use  the  collodion 
as  a  carrier. 


MINOR  SURGICAL  OPERATIONS 

LECTURE  LXI 
MINOR  SURGICAL  OPERATIONS 


Castration 

This  is  a  very  common  and  useful  operation  which  the  stock- 
man should  understand.  Colts  should  ordinarily  be  castrated 
by  qualified  veterinarians. 

Age. — Calves  may  be  castrated  at  almost  any  age,  but  better 
at  between  two  and  four  months.     Colts  may  be  operated  on  at 


i-'iG.  !»:.'.  -To  Throw  Cattle.     (J/.  ]{.  E.) 
Pull  straight  back  on  the  rope. 

any  age  after  a  few  months  old,  but  better  at  about  one  year — 
usually  under  two  years;  Iwmhs  at  one  to  three  weeks  and  pigs 
any  age,  but  better  about  two  weeks  before  or  two  or  three 
weeks  after  weaning. 

Restraint. — Calves   small   enough   to   be   handled   easily   are 

291 


292 


VETERINARY  STUDIES 


usually  held  on  the  ground,  clean  grass  preferred,  with  the  top 
hind  leg  held  forward ;  older  calves  and  bulls  may  be  easily 


Fig.  93, — Eestraint  for  Castration.     (White.) 


operated  standing  if  well  confined.     Look  out  for  kicks,  espe- 
cially from  older  bulls.     For  the  standing  operation,  it  is  safer 

to  confine  the  hind  legs  by  a  figure  8 
rope  tie  above  the  hocks  or  by  ordi- 
nary hock  kicking  hobbles,  or  to 
throw  and  tie  securely  in  some  eases. 
Yonng  pigs  are  held  by  an  assist- 
ant in  either  of  several  convenient 
ways.  Heavier  shoats  are  usually 
castrated  on  the  ground,  clean  grass, 
held  with  the  top  hind  leg  forward 
by  an  assistant.  Or  they  may  be 
''hog  tied"  for  the  two  front  and 
upper  hind  leg.  A  heavy  boar  may 
be  tied  short  by  a  loop  around  the 
upper  jaw  and  castrated  standing. 
In  this  case  it  is  advisable  to  have 
two  assistants  hold  a  pole  under  the 
belly,  well  back,  to  keep  the  boar 
from  lying  down.  The  standing 
operation  on  boars  is  inconvenient  for  some  operators.  See 
Figure  93. 


Fig.  94. — General  View  of 

Scrotum  and  Sheath. 

(White.) 

A,  A,  Long  incisions  par- 
allel to  the  median  line  BC. 


MINOR  SURGICAL  OPERATIONS  293 

Young  lamhs  are  held  by  an  assistant  and  may  be  docked 
at  the  same  time. 

Large  rams  may  be  "hog  tied"  like  the  boar  on  the  ground, 
except  that  the  lower  hind  leg  should  be  included  in  the  tie. 
The  upper  may  be  either  held  forward  or  included  in  the  tie. 
Older  lambs  and  small  rams  may  be  held  on  the  rump,  belly  up 
somewhat  as  for  shearing,  the  assistant  holding  both  hind  legs. 

Season.— Good   weather   is   desirable   especially    for  lambs— 


Fig.  95. — A  Good  Type  of  Emasculator.     (White.) 

usually  spring  or  fall.     Dust  should  be  avoided;  therefore  a 
quiet  day  is  preferred. 

Operation. — The  scrotum  incisions  should  be  parallel  to  and 
reasonably  near  the  median  line  or  "seam."  See  Figure  94. 
This  should  be  done  with  a  free  sweeping  cut  and  few  move- 
ments. Except  in  case  of  a  ruptured  animal,  young  boar,  for 
instance,  the  incision  should  go  through  the  thin  transparent 
sac  ^  around  the  testicle.  The  incision  should  be  reasonably 
long  and  extend  to  the  lowest  point  where  pus  could  otherwise 

collect. 

The  testicle  is  removed  in  various  ways,  the  choice  depending 
principally  on  the  danger  of  hemorrhage.  For  lambs  under 
about  three  weeks,  the  cord  is  simply  pulled  in  two  after  free- 
ing the  testicle.  For  pigs,  calves  and  older  lambs,  the  blood 
vessels  may  be  divided  by  moderate  pulling  and  slow  scraping 

'■  Peritoneum. 


294  VETERINAEY  STUDIES 

with  the  castrating  knife,  the  rest  of  the  cord  having  been  cut 
first. 

For  still  older  animals,  an  emasculator  of  the  type  shown  in 
Figure  95  is  desirable  both  for  convenience  and  safety.  It  is 
well  to  hold  the  cord  in  the  emasculator  for  a  little  while  after 
closing  the  jaws. 

Dangers. — On  account  of  the  peculiar  anatomy  of  the  parts 
involved  in  castration,  there  are  several  possibilities  of  trouble. 
The  student  should  understand  that  the  peritoneal  or  belly 
cavity  is  continuous  with  the  inguinal  canal  and  sac  around  the 
testicle.  As  the  testicle  of  the  young  animal  descends  from  the 
belly  to  the  scrotal  cavity,  it  carries  with  it  the  peritoneum, 
which  forms  a  thin  membranous  sac  closely  around  the  testicle. 

Thus  an  infection  of  the  interior  of  the  scrotum  or  stump  of 
the  cord,  after  removing  the  testicle,  easily  leads  by  extension 
directly  to  the  abdominal  peritoneum  and  to  a  fatal  peritonitis. 

Dangerous  hemorrhage  sometimes  occurs  after  this  operation, 
hence  the  necessity  of  keeping  recently  castrated  animals  under 
observation  for  a  few  hours.  For  control  of  hemorrhage,  see 
Lecture  on  Wounds.  Such  hemorrhage  is  usually  due  to  too 
rapid  scraping  or  to  accidental  nicking  of  the  artery  above  the 
point  of  division  or  to  a  poor  emasculator.  Some  animals  are 
natural  bleeders,  i.e.,  their  blood  does  not  clot  and  they  bleed 
dangerously   from  wounds  that  would  be   trivial   for  another. 

An  incomplete  or  inguinal  hernia  may  be  overlooked  and  the 
intestines  come  out  after  castration.  Examine  for  such  hernia 
before  removing  the  testicle. 

Premature  closure  of  the  incision  may  occur  especially  if  the 
incision  is  too  small.  Such  closure  prevents  proper  drainage  and 
favors  dangerous  disorders,  leading  to  much  swelling  and  even 
to  peritonitis.  Make  a  reasonably  long  incision  at  the  proper 
place.    If  necessary,  reopen  the  wound  with  clean  fingers. 

Allow  plenty  of  mild  exercise  beginning  as  soon  as  danger 
from  hemorrhage  is  past. 

Dehorning 

There  are  several  ways  of  performing  this  useful  operation, 
all  intended  to  either  prevent  the  horn  growth  as  in  case  of 
young  calves,  or  else  to  so  remove  the  horn  as  to  avoid  the 
growth  of  an  unsightly  stub. 


MINOR  SURGICAL  OPERATIONS  29o 

Age. — Young  calves  to  be  treated  by  the  caustic  method,  must 
be  treated  at  about  3  to  5  days,  preferably  not  over  7  days  old. 
After  this  a<ie  it  is  better  in  most  cases  to  wait  until  cattle  are 
about  two  years  old.  Young  cattle  at  two  years  handle  and 
dehorn  more  easily  than  when  nnich  older.  Aged  cattle  may  be 
deliorned  but  the  horn  is  hard  and  more  brittle. 

Caustic  method. — This  is  applicable  only  for  young  calves. 
Clip  the  hair  around  tlic  horn  button;  apply  a  broad  ring  of 
vaseline  around  the  button,  then  the  caustic.  This  is  a  stick  of 
either  caustic  soda  or  caustic  potash.  Wrap  paper  around  one 
end  of  the  stick  to  protect  the  fingers.  Dip  the  other  end  in  a 
cup  of  watei".  Shalr  off  surplus  ivater  and  rub  the  button  with 
the  moist  caustic ;  then  turn  the  calf  over  and  treat  the  other 
side  in  the  same  way.  Treat  each  button  two  or  three  times  at 
intervals  long  enough  to  let  the  horn  button  drv.  Do  not  allow 
water  from  the  caustic  to  fall  on  or  run  down  over  the  skin, 
and  do  not  allow  treated  calves  to  be  out  in  a  i)ossible  rain  for 
a  week  or  more. 

If  this  operation  is  properly  done,  there  follows  a  smooth 
poll. 

Older  cattle  should  be  well  confined  that  the  horn  may  be 
removed  with  saw  or  clippers.  It  is  well  to  take  about  a  quar- 
ter inch  of  skin  and  hair  entirely  around  the  horn.  When 
hastily  done  on  a  struggling  animal,  the  cut  is  apt  to  be  too 
high  at  some  point  and  an  unsightly  stub  results.  For  young 
cattle,  the  clipper  is  quick  and  satisfactory.  For  older  cattle  a 
narrow  blade  saw  (e.g.,  "meat  saw")  usually  does  better  work 
than  the  clipi)er.  The  blade  should  be  about  an  inch  wide  and 
well  stretched  in  a  strong  frame.  Tlie  saw  has  a  furthei'  ad- 
vantage in  dehorning  old  cattle  in  that  it  causes  less  hemorrhage. 

AVhere  many  cattle  are  to  be  dehorned,  it  usually  pays  to  pre- 
pare a  good  chute  intended  especially  for  this  purpose.  Cuts 
and  directions  for  constructing  such  chutes  are  given  in  federal 
Department  of  Agriculture  and  various  state  bulletins. 

A  few  cattle  may  be  dehorned  by  throAving  or  by  securing  the 
head  to  a  tree  or  to  an  overhead  stanchion  sup])ort. 

Suggestions. — If  dehorning  is  carefully  done  at  a  jn-oper  sea- 
son, dressing  or  treatment  of  any  kind  is  not  usually  needed. 
Serious  hemorrhage  is  rare  and  may  be  controlled  by  pressure 
pad  and  bandage  or  by  lislitly  l)urning  the  bleeding  point  with 
the  red  hot  end  of  a  small  bolt  or  end  gate  rod. 


296  VETERINARY  STUDIES 


Docking 


The  docking  of  lambs  is  a  simple  and  very  useful  operation, 
and  may  be  done  at  the  time  of  castration,  i.e.,  at  7  to  14  days 
old.  The  tail  is  cut  off'  preferably  at  an  articulation  between 
the  vertebra?,  leaving  a  stump  of  about  one  and  a  half  inches, 
with  enough  skin  for  covering  the  bone  and  good  healing.  This 
is  secured  by  pushing  the  skin  of  the  tail  toward  the  body  be- 
fore cutting. 

The  cutting  may  be  done  with  chisel  and  block  of  wood  or 
hand  pruning  shears  or  by  an  ordinary  castration  emasculator. 

If  chisel  or  pruning  shear  is  used,  older  lambs  may  bleed  seri- 
ously. For  such  lambs  docked  by  shear  or  chisel  the  tail  should 
be  tightly  tied  with  string  somewhat  above  the  point  of  inci- 
sion. It  is  much  more  convenient  to  do  this  before  cutting  off 
the  tail.     The  strings  should  be  removed  after  a  few  hours. 

A  good  emasculator  removes  the  tail  without  causing  hemor- 
rhage. Further  treatment  of  the  w^ound  after  operation  is 
usually  unnecessary. 

Abscess 

It  is  sometimes  necessary  for  a  stockman  to  open  an  abscess. 
As  a  rule  the  operation  is  reasonably  safe  where  the  abscess  is 
superficial  and  "pointing,"  i.e.,  distinctly  soft  at  some  point 
near  the  surface.  Some  judgment  is  necessary  in  considering 
the  location  and  proximity  to  important  structures,  like  articu- 
lations or  well  known,  large  blood  vessels.  The  purpose  of  this 
operation  is  merely  to  get  a  foreign  and  harmful  substance,  pus, 
out  of  the  way  of  nature's  healing  processes. 

Procedure. — ]\Iake  an  incision,  usually  at  the  point  where  the 
abscess  is  softest  under  pressure,  and  then  extend  it  freely  to 
the  lowest  point  where  a  pocket  could  otherwise  form.  For  the 
first  incision  by  an  inexperienced  operator,  something  like  a 
cork  may  be  slipped  over  a  slender  blade  to  control  the  depth 
and  extent  of  the  incision. 

The  animal  should  be  well  confined;  otherwise  an  unexpected 
movement  may  cause  slashing  incision.  For  any  such  operation 
there  should  be  at  hand  one  or  two  pairs  of  snap  artery  forceps 
for  clamping  on  a  possible  bleeding  vessel. 

Treatment. — Free  drainage  is  all  that  is  necessary  in  many 
cases.    After  the  pus  cavity  has  been  drained  it  may  be  desir- 


MINOR  SURGICAL  OPERATIONS  297 

able  to  wash  the  cavity  with  plain  water  or  w^ater  which  con- 
tains a  teaspoonful  of  salt  to  the  qnart. 

]Most  of  the  treatment  commonly  given  such  cases  by  stock- 
men is  harmful  rather  than  useful. 

In  some  cases  antiseptic  cleansinor  is  necessary;  usually,  how- 
ever, little  is  needed  but  simple  cleanliness  and  protection  from 
iiies. 

Tapping  for  Bloat 

Tapping  for  bloat  is  not  difficult.  It  is  reasonably  safe  for 
cattle  and  often  very  urgently  necessary  for  sheep.  Tapping  a 
bloated  horse  is  a  different  matter,  however,  and  must  be  done 
by  a  qualified  veterinarian. 

The  purpose  of  this  operation  is  to  quickly  let  out  gas  which 
has  accumulated  to  a  dangerous  extent  in  the  first  stomach. 

Cattle  and  sheep  bloat  chiefiy  in  the  rumen  or  paunch.  This 
is  so  large  when  an  animal  is  bloated  that  there  is  no  danger  of 
injuring  the  paunch  except  by  the  small  puncture  made  by  the 
trocar.     See  Figure  78. 

Procedure. — Disinfect  the  skin,  e.g.,  by  tincture  of  iodin,  in 
the  left  flank  rather  high  and  well  forward.  See  Figure  77. 
If  the  skill  is  too  thick  and  tough  for  the  trocar  point,  make 
a  small  incision  in  the  skin  only,  and  then  thrust  in  the  trocar 
and  cannula.  Gas  will  usually  escape  rapidly  and  the  respiration 
is  relieved.  If  the  tube  becomes-obstructed  by  stomach  contents, 
insert  the  trocar  or  a  clean  stick.  The  tube  (cannula)  may  be 
left  in  as  long  as  usually  needed. 

Subsequent  treatment  of  the  small  wound  is  unnecessary,  ex- 
cept another  local  treatment  by  iodin  when  the  cannula  is 
withdrawn. 

Abscesses  occasionally  follow,  but  as  a  rule  are  easily  treated 
and  are  not  serious. 

Removing  Warts 

The  removal  of  warts  in  ordinary  cases  is  a  simple  operation 
and  usually  successful  when  well  done.  There  are  various 
methods. 

Bjj  incision,  the  wart  may  be  removed  with  a  narrow  ring  of 
normal  skin.  A  sharp  pair  of  curved  surgical  shears  is  very 
convenient  for  this  and  many  other  surgical  operations. 

After  hemorrhage  is  checked,  apply  cau.stie,  c.r/.,  nitrate  of 


298  VETERINARY  STUDIES 

silver  in  stick  form  or  the  point  of  a  hot  iron,  or  the  point  of 
a  large  copper  sulphate  crystal. 

Warts  that  stand  well  out  from  the  skin,  with  narrow  base, 
may  be  successfully  tied  off  by  a  stout  linen  thread.  In  this 
method  the  thread  is  tied  tightly  around  the  base  of  the  wart 
as  low  as  possible,  and  left  there.  In  a  short  time  the  wart 
drops. 


ITs^DEX 


Abortiox,  257 

infectious,  259 
Abscess,   296 
Actinomycosis,  159 
Air  in  relation  to  disease,  106 
Alcohol,  282 
Aloes,  2S1 
Alum,   289 
Ammonia,    aromatic    spirits 

282 
Anatomy,  1 
Anemia,  kinds  of,  78 
Anthrax,   16.? 

symptomatic,  167 
Arm,   10 
Arteries,  46 
Articulations,  24 

disorders  of,   27 

structures  at,  25 

varieties  of,  25 
Astringents,  289 
Atrojihy,   84 

kinds  of,  84 
Azoturia,  218 

Bacteria,  96 

bo<lily  resistance  toward,  99 

body  entrance,  98 

classification  of,  99 

how  scattered,  97 

method  of  injury,  98 
Bichloride   of  mercury,   284 
Blackk'jr.  167 
Bloat,   2.S0 

tapping  for,  297 
Bones,   1 

development  of,   1 

kinds   of,    1 

structure  of,  2 
Bones  and  regions,  10 
Boracic  acid,  284 
Bots,  141 
Brain,  35 

divisions,    'A6 

functions,  35 

Camphor,  283 
Canker  sore  mouth,  174 
Capped  hock,  245 
Carbolic  acid.  284 
Castration,   291 


of, 


Catarrli,   sheep,   156 
Cathartics,  281 
Chloroform,  288 
Choke,  238 
Circulation,  42 

apparatus,  43 

disorders  of,  50 

heart,  44 
Collapse,  86 
Collodion,  290 
Corns,  246 

Constipation,  swine,  216 
Contagium,  96 
Corrosive  sublimate,  284 
Cowpox,  272 
Curb,  245 


AND    INFILTRATIOXS, 


Degenerations 

85 
Dehorning,  294 
Dietetic  diseases,  218 
Digestion,  physiology  of,  64 

carbohydrates,  64 

fats,   65 

proteins,  65 
Digestive  apparatus,  57 

liver,  61 

pancreas,  61 

salivary  glands,  57 
Disinfectants,   103 
Disinfection,  102 
Docking,   296 
Drenching,  280 
Dropsy,  83 
Dumniv,  247 
Dystokia,  274 

Elephant  leg,  222 
Embryotomy,  277 
Enteritis,  necrotic,  176 
Epsom  salts,  281 

Eever,  80 

Flies,  127 

Food  as  cause  of  disease,  119 

Foot   (horse),   10 

Foot,  anatomy  of,  19 

Foot-and-mouth  disease,  177 

Foot-rot,  171 

Forearm,  10 

Foul-foot,   173 


200 


300 


INDEX 


Founder,  224 
Tront  limb,  10 
disorders  of,  12 

Garget,  269 

Gentian,  283 

Gestation,  normal  periods  of,  257 

Ginger,  283 

Glanders,  203 

Heart,  disorders  of,  248 
Heaves,  227 
Hemorrhage,  S3 
Hemorrhagic  septicemia,  ISO 
Heredity     in     relation     to     disease, 

106 
Hog  cholera,  208 
Hoof,  20 
Hoven,  230 
Hygromas,  246 
Hyperemia,  77 
Hj-pertrophy,  84 

Inflammation,  79 
lodin,  285 
Iodoform,  285 

Lameness,  252 

Laminitis,  224 

Leg,  15 

Lice,  125 

Lime,  common,  285 

Linseed  oil,  282 

Lip-and-leg  ulceration,  174 

Lumpy  jaw,  159 

Lungs,  congestion  of,  swine,  216 

Lymphangitis,  222 

Lymphatic  system,  48 

Magnesium  sulphate,  281 
Mammary  glands,  72 

disorders  of,  75 
Mammitis,  269 
Mange,  137 

cattle,  138 

horse,  138 
Matrix   (foot),  21 
Medicines,  administration  of,  280 

common,  280 
Mercury,  bichloride  of,  284 
Metritis,  265 
Milk  fever,   233 
Muscles,  31 

disor(lers  of,  32 

structure  of,  30 
Muscular  system,  29 

Nasal  grub,  154 
Navicular  disease,  246 
Necrophorus,  168 
Nematodes,  142 


Nerves,  37 

cranial,  37 

spinal,  37 
Nervous  system,  33 

disorders  of,  39 

nerve  centers,  33 

nerve  fibers,  34 
Nitre,  sweet  spirits  of,  287 
Nodule  disease,  145 

injury  done,  146 

prevention,   148 

treatment,  147 

Obstetrics,  254 
Opium,  288 
Osseous  tissue,  89 
Ovaries,  254 

Parasites,  124 

efPect  on  health  of  host,  124 

external,  125 

internal,   141 

nourishment  of,  124 

parasitic  diseases,  124 
Parasitism,  136 

general  treatment  for,  125 

practical    suggestions    concerning, 
125 
Parturient  paralysis,  233 
Parturition,  accidents  of,  265 

difficult,  274 
Pathology,  77 
Pelvis,  5,  14 
Perineum   ruptured,  248 
Plantar  cushion,  21 
Posterior  limb,  14 

disorders  of,  17 
Posterior  paralysis  (swine),  215 
Potash,  nitrate  of,  287 
Pregnancy,  accidents  of,  257 
Presentations,  faulty,  274 

normal,  274 

Quittor,  246 

Eespiration,  51 
Eespiratory  system,  53 

parts,  53 
Eetention  (of  fetus),  264 

(placenta  or  afterbirth),  267 
Ribs,  9 

Ringbone,  242 
Ringworm,  128 

SiDEBONE,   243 
Spavin,  243 
Splints,  245 
Sodium  l)romid,  288 
Sodium  chlorid,  286 
Sodium  hyposulphite,  286 
Sodium  sulphite,  286 


INDEX 


301 


sternum,  9 
Stomach  worms,  149 

medical  treatment,  lol 
Salt,  common,  286 
Saltpeter,  287 
Sheep  scab,  130 

how  spread,  131 

possible  mistakes,  134 

treatment,  134 
Sheep  tick,  127 
Shoe  boil,  245 
Shoulder,  10 
Stomatitis,  174 
Surgical  operations,  291 
Swine  diseases,  215 
Symptomatic  anthrax,  167 
Syncope,  86 
Synovia,  26 
Synovial  sacs,  246 

Tannic  acid,  290 
Tape  worms,  143 
Teats,  disorders  of,  271 
Teeth  and  dentition,  3 

age,  estimating,  3,  4,  5 
Teeth,  disorders  of,  6 
Texas  fever,  185 
Tick  fever,  185 


Ticks,  128 
Tuberculin  test,  198 
Tuberculosis,  192 
Turpentine,  287 
Tympanites,  230 

Udder,     diseases     and    accidents, 

269 
Urinary  organs,  68 

disorders  of,  70 
Unsouncbiess,  horse,  241 
Uterus,  254 

inversion  of,  264 

Veins,  47 
Ventilation,  109 

considerations  affecting,  114 

natural  forces  affecting,  112 

necessity,  110 

sjiace  needed,  114 
Verminous  bronchitis,  153 
Vertebrae,  7 
Volvulus,  264 

Warts,  272 

Water,  cause  of  disease,  121 

Womb,  254 

Wounds,  88 


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